1.1. Acoustic correlates of focus

Previous studies have shown duration, f0, and intensity to be the primary acoustic correlates of focus marking in English (Weismer & Ingrisano, 1979; Folkins et al., 1976; Atkinson, 1973; Breen et al., 2010; Cooper et al., 1985; Eady et al., 1986; Eady & Cooper, 1986; Kochanski et al., 2005; O’Shaughnessy, 1979; Pell, 2001; Roettger et al., 2019). However, there is a notable variety in the reported findings, which is likely at least partially due to studies differing with regard to investigated dialects and populations, as well as methods. In particular, it is likely that the use of different subsets of acoustic correlates with varied definitions examined in these studies likely have contributed to the mixed findings, making it difficult to evaluate how focus effects systematically manifest in different acoustic correlates. Also, the effects of lexical stress and focus were not clearly delineated or controlled in many of the earlier studies, partly because lexical stress and focus placement are closely related (Turk & White, 1999). Therefore, the current study aimed to examine the effects of focus on a variety of acoustic correlates and build on the previous findings in different varieties of English to gain a more precise understanding of how focus is produced in a single dialect, Canadian English.

Focus-induced lengthening has been consistently observed in previous studies, but there are substantial inconsistencies regarding temporal modulation of words or segments preceding or following focus. For instance, Cooper et al. (1985) and Eady & Cooper (1986) reported lengthening of the focused item without shortening of adjacent words, while Weismer & Ingrisano (1979) and Folkins et al. (1975) found post-focal shortening in addition to focus-induced lengthening on the focused item. Eady et al. (1986) replicated this post-focal shortening effect, but only in shorter sentences (5–7 syllables) and not in longer sentences (10–12 syllables) used in the experiment. Pell (2001) found the post-focal shortening effect in both short (6 syllables) and long (10 syllables) sentences. In terms of pre-focal shortening, Pell (2001) observed pre-focal shortening in long sentences, contrary to studies that did not find shortening preceding focus (Weismer & Ingrisano, 1979; Cooper et al., 1985; Eady & Cooper, 1986).

Intensity has been argued to be another primary acoustic correlate of focus, but this is partly based on earlier findings that greater intensity is associated with lexical stress in English: Fry (1955), Lieberman (1960), and Beckman (1986) observed an increase in the amplitude of the stressed syllable compared to unstressed syllables, and Turk & Sawusch (1996) showed that the contribution of intensity to predicting lexical stress in perception was significant, although its independent contribution in the absence of duration information was small. Kochanski et al. (2005) provided evidence for loudness as a better predictor for detecting prominent syllables than f0, using a corpus of spontaneous speech in seven dialects of British and Irish English. This finding is in contrast to previous studies that found f0 to be a major correlate for prominence. For instance, Xu & Xu (2005) found an expansion of f0 range to be associated with focus and a compression of f0 range with post-focal material, suggesting that f0 makes an independent contribution to the production of focus.

In addition, there is no clear agreement concerning the phonetic details of focus effects on f0. Many previous studies observed higher f0 to be associated with focus, followed by a sharp drop in f0 (Atkinson, 1973; O’Shaughnessy, 1979; Cooper et al., 1985; Eady & Cooper, 1986; Eady et al., 1986; Pell, 2001). However, how and where f0 was measured (e.g. mean or peak, syllable or whole word) and what constitutes a higher f0 also differed between studies, with some reporting a paradigmatic change, e.g., comparing the realization of a word in narrow focus to the realization of the same word in a broad focus sentence, and others a syntagmatic change, e.g. comparing a focused word to the pre- and post-focal words in the same sentence. For example, Atkinson (1973) described a lowering of f0 after a syllable in an emphasized word and discussed how the f0 fluctuation makes the syllable stand out from the rest of the utterance. He also found that this lowering is sometimes accompanied by a higher f0 (peak and mean) of the prominent syllable compared to the same syllable in the same utterance produced without an emphasis on the word. On the other hand, O’Shaughnessy (1979) only stated that emphasis results in larger f0 obtrusions in the emphasized syllables compared to the other syllables in the utterance. Later studies such as Cooper et al. (1985), Eady et al. (1986) and Pell (2001) compared the mean f0 of the focused item with the mean f0 of the corresponding item produced in the neutral condition.

Nevertheless, a post-focal f0 decrease has been observed relatively consistently compared to an f0 increase on a focused item. In particular, Cooper et al. (1985) argued that this post-focal f0 drop, rather than the increased f0 on the focused words, is the major effect of focus in sentence-initial and sentence-medial positions (also see Sánchez-Alvarado, 2020; Arnhold, 2021), whereas Eady et al. (1986) observed a lack of post-focal f0 drop when there was an additional focused word later in the utterance (i.e., in a double-focus condition), which appears to undermine the claim. Eady et al. (1986) also reported a higher f0 peak in the sentence-initial focused word, which was not found consistently in the previous studies (Cooper et al., 1985 with f0 peak; Eady & Cooper, 1986 with f0 peak; Sánchez-Alvarado, 2020 with f0 range; Arnhold, 2021 with f0 peak). Moreover, pre-focal f0 mean lowering shown in Atkinson (1973) and Eady & Cooper (1986) was not found in Pell (2001).

More recently, Breen et al. (2010) examined a relatively large number of acoustic correlates to investigate whether and how they are employed to systematically distinguish between focus on different constituents (subject, verb, object), focus breadths (narrow object focus vs. broad focus), and types of focus (contrastive vs. non-contrastive) in American English. The results of a series of production experiments showed that the focused constituent was signalled with longer duration, higher f0 mean and maximum, and higher maximum intensity, compared to pre- and post-focal words. In addition, objects with narrow focus were marked by longer duration, higher f0 mean and maximum, and higher maximum intensity compared to objects with broad focus. Interestingly, subjects and verbs with contrastive focus were produced with lower f0 mean and maximum than those with noncontrastive narrow focus, contrary to previous studies that found higher f0 to be associated with contrastive focus (Ladd & Morton, 1997 for British English; Ito & Speer, 2008 for American English).

It is crucial to acknowledge that these previous studies examined different varieties of English using different tasks to elicit the speech data, which has likely contributed to the mixed findings on prosodic focus marking. In an attempt to address the resulting contradictions and gaps in the literature, the present study examined the prosodic marking of focus in Canadian English, taking into account a broad range of acoustic correlates and directly comparing realizations of broad focus, narrow contrastive focus and given (or background) information in the sentence-initial, -medial and -final positions (see 1.5 for the hypotheses).

1.2. Pitch accents and focus

Information structure is also phonologically signaled by pitch accents. Studies on pitch accents or focus in American English suggest that a H* (or L+H*) accent is associated with new information (or contrastive focus) and a L* or absence of pitch accent (or de-accenting) is associated with given information. For example, Pierrehumbert & Hirschberg (1990) argued that new information is rendered salient by a H* while given information does not bear a pitch accent or receives a L*. They also suggested that a L+H accent marks the salience of a scale: a L*+H accent signals a lack of speaker commitment, while a L+H* signals that the speaker asserts that the accented item should be believed over a possible alternative. In other words, under this account, a L+H* can be characterized as a contrastive accent. Similarly, Steedman (2008) characterized H* accents as signalling uncontentious rhemes (a notion that can be roughly equated with focus or new information) and L+H* as uncontentious themes (a notion corresponding to topic or givenness). Welby (2003) showed that listeners are indeed sensitive to the presence or absence of a pitch accent when perceiving the information structure of an utterance. Theoretical accounts also generally agree that the representation of information structure is closely related to the location and type of pitch accent (Büring, 2007; Selkirk, 1995; Truckenbrodt, 1995).

However, empirical studies provide evidence that the relationship between information structure and the pitch accent types is less straightforward than previously considered (Terken & Hirschberg, 1994; Ito et al., 2004; Hedberg & Sosa, 2007; Chodroff & Cole, 2019). Ito et al. (2004) found that while the L+H* pitch accent was more likely to appear in contrastive contexts than non-contrastive contexts, it did appear in non-contrastive contexts in both new and given conditions of information status. De-accenting was also not exclusively found in the given condition. Chodroff & Cole (2019) argued for a probabilistic relationship between information structure and the type of pitch accent on the target word: Given information was more likely to appear with a L* or no pitch accent, whereas new and contrastive information were more likely to appear with H* or L+H*. Their results also showed that, similarly to what Ito et al. (2004) reported, (L+)H* pitch accents were observed on target words in the given condition, and new and contrastive target words with L* or no pitch accent were also observed (also see Grice et al., 2017, for a similar conclusion on German).

The current study investigates how different pitch accents are associated with information structure in Canadian English by analyzing the presence/absence, as well as the types of pitch accents occurring in broad focus, narrow contrastive focus and on pre- and post-focal given constituents. We hypothesize that H* and L+H* are more likely to appear in the items in contrastive condition than given condition, while L* and the absence of an accent are more likely to be observed in items in given than contrastive condition. In addition, the possibility remains that the division between the types of pitch accents occurring in contrastive/given condition is not clear-cut, such that some contrastive constituents do not appear with (L+)H* or some given items appear with pitch accents that are not L*.

1.3. Dialectal variations in focus production

Dialectal variation has been argued to be one of the factors that systematically modulate acoustic correlates of focus, which can lead to phonological and/or phonetic differences. For example, differences pertaining to pitch accent inventories and tonal alignment in the varieties of Indian English (Maxwell & Payne, 2018), different pitch accent types (i.e., rising vs. falling) associated with focused elements between Indian and British English (Féry et al., 2016), and differences in the pitch accent alignment between Scottish Standard English and Southern British English (Ladd et al., 2009) have been reported. In addition, O’Reilly et al. (2010) examined f0 values and contours to investigate how broad and narrow contrastive focus are realized in Donegal varieties of Irish (Gaelic) and Irish English. The results suggest that contrastive focus is produced with a large f0 excursion and post-focal f0 lowering compared to broad focus in Irish English, as has been reported previously for other varieties of English (cf. section 1.1). However, there are some characteristics that do not align with some of the earlier results reported for different varieties of English: f0 lowering before contrastive focus was observed (contra. Xu & Xu, 2005 for American English) and broad focus was associated with a rising (L*H) pitch accent (contra Chen et al., 2007 for Southern British English).

Turning to the regional dialects of American English, Arvaniti & Garding (2007) showed evidence that phonological and phonetic differences in focus production may exist between Minnesotan English and Southern Californian English. The use of H* and L+H* in their Southern Californian speakers was modulated by the number of iterations of the target word, whereas the Minnesotan speakers used L+H* irrespective of the number of repetitions, suggesting that H* may not be used in Minnesotan English. In addition, the alignment of pitch accents investigated in this study was generally later in Southern Californian speakers than Minnesotan speakers. Arvaniti & Garding (2007) also noted other differences in phonetic details of pitch accents between their findings and some earlier studies, which the authors argued might be due to the different varieties of American English. For instance, the L tone target of the L+H* was found to be aligned within the accented syllable in their data, whereas it was observed to be aligned with the preceding syllable in earlier studies (Pierrehumbert, 1980; Beckman & Pierrehumbert, 1986). A similar cross-dialectal phonological difference in pitch accent inventories was reported in Clopper & Smiljanic (2011) as tentative findings: A relatively stronger preference for L* pitch accents was observed for Southern American English speakers than Midlands American English speakers.

Previous studies on the relationship between different pitch accents and information status also showed cross-dialectal differences in the interpretation of pitch accents. Chen et al. (2007) investigated the role of four nuclear pitch accents in the processing of information status in Southern British English, building on previous findings in German (Baumann et al., 2006) that different pitch accent types are associated with different types of information status. The authors of this eye-tracking study found that speakers of Southern British English associated fall (H*L) and rise-fall (L*HL) pitch accents with new information, while rise (L*) pitch accents were associated with given information. This differs from how listeners of American English associate different pitch accents with information status. In an eye-tracking experiment, Watson et al. (2008) found that L+H* created a strong bias towards contrastive (and given) information, whereas H* created bias towards both contrastive and new information, suggesting that interpretations of H* and L+H* pitch accents in American English are neither mutually exclusive nor variations of a single pitch accent category.

Empirical findings thus established that different varieties of English realize focus differently. However, Canadian English has been assumed to be a subgroup of American English (Bloomfield, 1970) or intermediate between American and British English (Canepari, 2010), and little attention has been given to whether and how Canadian English may differ from the varieties of American English in terms of prosodic aspects (e.g., Wagner & McAuliffe, 2019, treat their Canadian English data as broadly representative of English). Moreover, the prosodic characteristics of Canadian English are usually not considered in the phonetic or phonological literature describing Canadian English (Chambers, 1973, 1991, 2006; Labov et al., 2005; Sundara, 2005; Boberg, 2008). A few exceptions gave minimal and/or impressionistic descriptions (Halford, 2007; Canepari, 2010), described a distinct dialect (Clarke, 2010 for Newfoundland English), or did not aim to address prosodic aspects specific to Canadian English (DePape et al., 2012). Some studies have investigated a particular phenomenon concerning phrase-level intonation called High Rising Terminal (HRT), also known as uptalk (Lacey et al., 1997; Shokeir, 2008; Sando, 2009; Ouafeu, 2009; also see e.g., Fletcher et al., 2005 on HRTs in other varieties of English). While the differences in Canadian and American English in vowel production have been relatively well studied (Joos, 1942; Clarke et al., 1995; Hagiwara, 2006), the prosodic differences between these two broadly defined varieties of English have been rarely investigated.

1.4. Focus in Canadian English

Only a few studies provide information on how focus is produced or perceived in Canadian English, although focus marking was not always the primary topic of the study. The primary goal of DePape et al. (2012) was not to investigate focus production in Canadian English, but rather to show how adults with autism spectrum disorder and varying levels of language functioning use prosodic features to mark information status. Nevertheless, the six speakers in the control group provided insight into how focus is marked in Canadian English: larger f0 falls were observed in the focused word regardless of the location of the word in an utterance (i.e., subject or object), and larger f0 rises in the focused word in sentence-final positions compared to given topics in the same position. Patience et al. (2018) examined the first pitch accents of statements and questions using a sentence repetition task. They found that H* is the dominant pitch accent type in short SVO sentences (e.g., Bobby looked for his football), taking up nearly 80% of all first pitch accents, while L*+H is also observed (approximately 15%).

Arnhold et al. (2020) is the only study to our knowledge that directly investigated how regional accent influences the perception of information structure in Canadian English. Experiment 1 was an eye-tracking study: Listeners of Canadian English were given auditory instructions spoken in Standard Southern British English and their eye movements were monitored while they moved a computer mouse to click and move objects presented on the monitor. The target words in the instruction sentences varied in pitch accent type (fall, rise, no accent) and information status (given, new). The results showed that Canadian listeners associated falling accents with new information, and interpreted unaccented words as given, just as British listeners responding to the same items (Chen et al., 2007). Crucially, the rising accents were not clearly associated with either given or new information. This finding, which is in contrast with the results of Chen et al. (2007) for British listeners, suggests that the way Canadian English uses pitch accents to mark information status differs from Standard Southern British English. Given the phonological differences observed between Canadian English and British English, one may assume that there are also phonetic differences in how the acoustic correlates of focus are employed in these varieties of English.

1.5. Hypotheses of the current study

We investigated the prosodic marking of information structure in Western Canadian English by analyzing a scripted speech corpus of 37 native speakers of Alberta and British Columbia English collected through a speech production experiment, which we compared to previous research on other varieties of English. Our main point of comparison was Mainstream American English (MAE), as it has been the subject of most previous research and due to the common assumption that Canadian English is vastly similar to MAE. Given the findings that suggest information structure is marked differently in different dialects of English, we hypothesized that the phonetic and phonological details of focus marking in Western Canadian English are different from those previously observed for MAE. By examining a variety of acoustic correlates to broad focus, narrow focus and given information, the current study aims to show whether and how they are modulated in a systematic way to mark information structure. By annotating and analyzing the types of pitch accents, another goal of the current study is to establish a core pitch accent inventory (limited to declarative sentences) in Canadian English and to test the relationship between information structure and the presence and types of pitch accents. Based on previous findings for other varieties of English, particularly MAE, the following hypotheses can be formulated:

• H1. Acoustic marking

  • a. Constituents with narrow contrastive focus have longer duration, higher intensity and higher f0 than given and broad focus constituents.

  • b. Pre- and post-focal given constituents have shorter duration, lower intensity and reduced f0 compared to broad focus constituents (may only hold true post-focally).

• H2. Pitch accents

  • a. Constituents with narrow contrastive focus are accented significantly more often than given and broad focus constituents, and frequently carry H* or L+H* accents.

  • b. Pre- and post-focal given constituents are accented significantly less often than broad focus constituents, and they carry L* accents where they are accented at all.

3.1. Results of the acoustic analysis

All models showed a significant interaction between Focus and Constituent (see the fixed effects summary tables in section 1 of the supplementary materials). Therefore, in this section, we focus on the results of the pairwise comparisons between individual factor level combinations, which are based on the Linear Mixed Effects Models for each acoustic correlate. Results of these comparisons are presented with compact letter display. The output of the pairwise comparisons are given in section 2 of the supplementary materials.

3.1.1. Duration

Figure 1 summarizes the results of the pairwise comparisons for constituent duration (also see Tables 1 and 8 in the Supplementary Materials), with the compact letters shown above each plotted median value denoting whether the differences between the conditions were significant. That is, if two conditions share one or more letter(s), they are not significantly different, whereas two conditions that do not share any of the letter(s) are significantly different. For example, the duration of subjects in the SF condition is marked with ‘cd’, whereas the duration of subjects in the BF condition is marked with ‘a’. The fact that they do not share a letter indicates that they differ significantly.

Figure 1

Durations of subjects, verbs, and objects in the four focus conditions. The letters and boxes reflect the results of the pairwise comparisons.

For additional clarity, the focus conditions without statistically significant difference are grouped together in grey boxes within each of the constituent panels, while the conditions that are significantly different from each other are be shown in separate boxes. For example, subjects (left panel of Figure 1) were significantly longer in the subject focus condition than the other conditions, and there was no significant difference among the other conditions for this constituent. Note that the grey boxes only highlight a lack of significant differences within constituents, whereas differences between constituents are only indicted by the letters. For example, in broad focus, subjects (labeled ‘a’) differed significantly from both verbs (‘de’) and objects (‘eg’), while verbs and objects did not differ significantly from each other, as indicated by the fact that both of their labels contain the letter ‘e’.

As Figure 1 shows, subjects in the subject focus condition (SF, label ‘cd’), which are narrow-focused, were significantly longer than broad-focused subjects (BF, label ‘a’). The difference between the estimated marginal means (EMMs) of the conditions is 57.62 ms. The same pattern of narrow-focused constituents being significantly longer than broad-focused constituents holds for verbs (‘fgh’ for VF; ‘de’ for BF with an EMM difference of 50.38 ms) and objects (‘h’ for OF; ‘eg’ for BF with an EMM difference of 21.81 ms).

Constituents in narrow focus were also significantly longer than given constituents. Subjects in the VF and OF conditions (given while verbs and objects received NF, respectively) are marked with ‘ab’, which does not share a letter with the letter display (‘cd’) for subjects in the SF condition, where subjects received NF. The EMM differences between SF, where subjects were in narrow focus, and the other two conditions were 44.73 ms for the VF condition and 45.63 ms for OF. This pattern is again repeated with verbs (‘bc’ vs. ‘fgh’ with EMM differences of 73.89 ms comparing VF to SF and 74.10 ms comparing VF to OF) and objects (‘cdf’ vs. ‘h’ with EMM differences of 54.30 ms for OF vs. SF and 64.65 ms for OF vs. VF).

Turning to comparing the constituents with BF with the given constituents, where another constituent was narrow-focused in the utterance, subjects with BF did not significantly differ from given subjects (‘a’ vs. ‘ab’), whereas verbs and objects with BF were significantly longer than given verbs and objects (‘de’ vs. ‘bc’ for verbs with EMM differences of 23.54 ms for BF vs. SF and 23.72 ms for BF vs. OF; ‘eg’ vs. ‘cdf’ for objects with EMM differences of 32.49 ms for BF vs. SF and 42.84 ms for BF vs. VF).

Lastly, comparing differences between the constituents, an effect of phrase-final lengthening was observed in a progressive manner: The phrase-final constituents, objects, were significantly longer than verbs in most conditions, and verbs in turn were significantly longer than subjects in all conditions.

3.1.2. Intensity

The intensity measure was calculated for each constituent as the difference between the mean intensity (dB) taken at the middle 50% portion of the vowel of the stressed syllable, which was always the second syllable of the constituent, and the average of the mean intensity (dB) values taken at the middle 50% portion of the vowels of the unstressed syllables preceding and following the stressed syllable. The larger the relative intensity, the greater the amplitude of the stressed syllable compared to the surrounding unstressed syllables within the constituent. Figure 2 shows that the mean estimates were always greater than 0 in all conditions, meaning that the stressed syllable was louder than the unstressed syllables in a constituent regardless of the constituent or focus conditions.

Figure 2

Intensity of subjects, verbs, and objects in the four focus conditions, calculated as the difference between the mean intensity of the stressed (i.e., second) vowel of the constituent and the average of the mean intensity of the preceding (i.e., first) and following (i.e., third) unstressed vowels of the same constituent. The letters and boxes reflect the results of the pairwise comparisons.

As shown in Figure 2 (also see Tables 2 and 9 in the Supplementary Materials), the relative intensity of the narrow-focused constituents was significantly higher than for the given constituents, regardless of the constituent. That is, the degree to which the stressed syllable was louder than the surrounding unstressed syllables was greater when the constituent was narrow-focused than when it was given. The comparison between NF and BF, however, was less straightforward: The relative intensity values of narrow-focused verbs were significantly higher than in broad focus, but subjects did not differ significantly between BF and SF and neither did objects show a significant difference between BF and OF. This indicated that, in terms of relative intensity, the object constituent was prominent in the broad focus condition, which was in line with previous literature on focus projection (e.g., Gussenhoven, 1983; Féry & Samek-Ludovici, 2006; Wagner & McAuliffe, 2019). In addition, the object constituent was the only one showing significantly higher relative intensity in broad focus than when it was given (i.e., in SF and VF), while given subjects and verbs did not differ significantly from broad focus.

Table 2

Summary of results concerning the modulation of the acoustic correlates to focus and givenness. A checkmark (✔) denotes that the results supported H1a with respect to comparisons between narrow and broad focus, whereas an exclamation mark (!) denotes the results contradicted H1a (i.e., significant difference in the opposite direction). Significant weakening adjacent to constituents with narrow focus supporting H1b is indicated with a checkmark in corresponding cells, specifying the condition(s) where it occurred. An empty cell indicates neither enhancement nor weakening was found.

	Pre-focal weakening			Focused constituent enhancement			Post-focal weakening
	S	V	O	S	V	O	S	V	O
Duration		✔Pre-OF		✔	✔	✔		✔Post-SF	✔Post-SF & Post-VF
Relative intensity					✔				✔Post-SF & Post-VF
F0 range									✔Post-SF & Post-VF
F0 maximum	✔Pre-VF & Pre-OF			!	!			✔Post-SF	✔Post-SF & Post-VF
F0 mean	✔Pre-VF & Pre-OF			!	!			✔Post-SF
F0 minimum				!	!			✔Post-SF

A syntagmatic comparison between the constituents in different focus conditions also showed that in BF, objects had higher relative intensity than both subjects and verbs, which did not differ significantly from each other. Further, the narrow-focused subjects and objects showed significantly higher relative intensity values than the two following (for subjects) or preceding (for objects) given verbs in SF and OF, respectively. In contrast, the relative intensity of the narrow-focused verbs was not significantly higher than the preceding subjects or the following objects in VF. In addition, subjects also had lower relative intensity than objects in OF, while in SF, the relative intensity of the verbs immediately following the narrow-focused subjects was significantly lower than the relative intensity of the following objects.

An evaluation of absolute mean intensity in the middle 50% portion of the vowel of the stressed syllable of each constituent (in dB, with all sounds scaled to 70dB before measurements) showed slightly different effects of the focus manipulation: The difference between narrow focus and given realizations of the same constituent observed here was not consistent, with only objects showing significant differences between narrow focus and both given conditions. Instead, analysis of this absolute measure indicated post-focal drops in intensity, with verbs having lower values in SF than in all other conditions and objects having lower values in SF and VF than in BF and OF. Finally, syntagmatic comparisons with the absolute measure also displayed lowering of intensity over the course of the utterance, with significant differences between the constituents appearing in all focus conditions (see Tables 3 and 10, and Figure 1 in the Supplementary Materials for details).

3.1.3. F0 range

As shown in Figure 3 (also see Tables 4 and 11 in the Supplementary Materials), the f0 range did not significantly differ between narrow and broad focus for any of the three constituents. For example, the f0 range values of the subjects were not significantly different between the BF and the SF conditions, and the same null effect was found for the f0 range values of the verbs and the objects. However, there were significant differences between the f0 range of the constituents in the narrow-focus condition and the given condition, as illustrated in Figure 3. For subjects, the f0 range in SF was significantly larger than the f0 range of the given subjects when either the verbs were focused or the objects were focused. Similarly, verbs with narrow focus had significantly larger f0 range values compared to verbs in the SF or the OF condition. Objects with narrow focus also showed significantly larger f0 range values compared to objects in the SF or the VF condition. Comparing broad focus and given realizations only showed significant differences for objects, which had smaller ranges in SF and VF than in BF.

Figure 3

f0 range (in st) of subjects, verbs and objects in the four focus conditions. The letters and boxes reflect the results of the pairwise comparisons.

Lastly, f0 range did not show a general decrease over the course of an utterance and few significant differences appeared between the constituents within a given focus condition.

3.1.4. F0 maximum

No significant difference was found between the f0 maxima of verbs and objects in the BF and narrow focus conditions (VF and OF, respectively), as illustrated in Figure 4 (also see Tables 5 and 12 in the Supplementary Materials). The f0 maximum of subjects in the BF condition was significantly higher than that in the SF condition, contrary to expectations. However, as expected, given subjects had lower maxima than subjects in BF. A similar pattern was found in the f0 maxima of given objects, which were significantly lower than those of objects in the BF and OF conditions. The f0 maximum of verbs in the SF condition was significantly lower than that of verbs in the BF and the VF conditions, which did not differ from that of verbs in the OF condition. That is, the presence of NF did not result in an f0 increase, but an f0 decrease was observed following a constituent with NF.

Figure 4

f0 maximum (in st) of subjects, verbs and objects in the four focus conditions. The letters and boxes reflect the results of the pairwise comparisons.

Finally, f0 maxima displayed a general downtrend over the course of an utterance. This resulted in significant differences between all constituents within a focus condition in all cases except for subjects and verbs in VF, i.e., a drop was only observed post-focally.

3.1.5. F0 mean

The f0 mean of subjects in the SF condition was significantly lower than in the BF condition, as shown in Figure 5 (also see Tables 6 and 13 in the Supplementary Materials). The f0 mean of subjects in the SF condition was also significantly lower than in VF and OF. However, the f0 mean values of verbs and objects in narrow focus were significantly higher than those in the SF condition, while not significantly differing from the f0 mean in the other given condition (OF and VF, respectively). This suggests that a narrow-focused constituent was followed by a sharp drop in f0, particularly for subjects, while the constituent with the narrow focus did not show an increase of f0 itself. This generalization is further supported by directly comparing constituents within each focus condition: The f0 mean showed a decrease from subjects to verbs, and then from verbs to objects, regardless of focus. One exception was the f0 mean values of verbs and objects, which did not differ when subjects were narrow-focused. It is possible that the f0 level of the verbs following the narrow-focused subjects were already low enough to be close to the floor of the speaker’s range, keeping the following element—objects—from manifesting a further decrease in f0.

Figure 5

f0 mean (in st) of subjects, verbs and objects in the four focus conditions. The letters and boxes reflect results of pairwise comparisons.

3.1.6. F0 minimum

As shown in Figure 6 (also see Tables 7 and 14 in the Supplementary Materials), the f0 minimum of subjects in the SF condition was significantly lower than in the BF and given conditions. For verbs, the f0 minimum in the VF condition was significantly higher than in the SF condition, although not significantly different from the BF and OF conditions. No significant difference was found for objects between the OF, BF and the given conditions, suggestive of a floor effect. Pairwise comparisons between the constituents within the same focus condition suggested that the f0 minimum of objects was significantly lower than that of verbs, which in turn was significantly lower than that of subjects, similar to the pattern observed in f0 means. The only difference was found, again, in verbs and objects in the SF condition, which did not differ significantly from each other. A post-focal f0 drop was observed in verbs after subject focus, but no focus-induced f0 increase was found on the focused constituent itself.

Figure 6

f0 minimum (in st) of subjects, verbs and objects in the four focus conditions. The letters and boxes reflect the results of the pairwise comparisons.

3.2. Interim summary of the results of the acoustic analysis

The acoustic correlates examined in the current study were systematically modulated by the focus conditions. The presence of narrow focus resulted in increased magnitudes of various correlates, most notably constituent duration, intensity and f0 range of the focused constituent relative to their realization in given conditions. The other f0 measures did not show enhancement effects due to narrow focus across the board: narrow-focused subjects were actually lower in f0 mean and f0 minimum than given subjects and comparable to given in f0 maximum. The f0 maximum, mean, and minimum of verbs were higher in the narrow focus condition than those in the post-focal given condition (i.e., subject focus) but not different from those in the pre-focal given condition (i.e., object focus). As for objects, the presence of narrow focus manifested as enhancement in some contexts (f0 mean compared to post-focal condition and f0 maximum) but not in the others (f0 mean compared to pre-focal condition and f0 minimum).

The comparison between narrow and broad focus revealed a complex pattern: while the durations of all constituents were longer under narrow focus than broad focus, only verbs showed enhancement of relative intensity under narrow focus compared to broad focus, and none of the constituents showed significant differences in f0 range between the narrow and broad focus conditions. With regards to the other f0 measures, objects did not show significantly differences between broad focus and narrow (object) focus, while narrow-focused subjects and verbs were even lower in f0 maximum, mean and minimum than subjects and verbs in broad focus, respectively.

Finally, comparing broad focus and given conditions showed that subjects showed lower f0 mean and f0 maxima in given conditions than in broad focus, while given objects had shorter durations, lower relative intensity, f0 ranges and f0 maxima than in broad focus. For verbs, durations were shorter in both given conditions (SF and OF) than in broad focus, while f0 maximum, f0 mean and f0 minimum were lower in SF compared to broad focus, suggesting clearer marking post-focally than pre-focally.

Overall, the hypotheses in H1 (see 1.5) were partially supported: narrow focus did not induce enhancement of all acoustic correlates in an across-the-board manner, although enhancement of duration, intensity, and f0 range in the narrow-focused constituents compared to given constituents were consistently observed. Given constituents differed not only from narrow focus, but also from broad focus realizations, though less extensively. As hypothesized, several measures showed consistent marking of givenness only post-focally.

3.3. Results of the pitch accent analysis

Figure 7 displays all constituents submitted to the pitch accent analysis, divided by the presence or absence as well as the types of pitch accents. The most frequent label was “no accent”, i.e., unaccented constituents (35% of the data; 860 constituents). Among the accented constituents, the dominant pitch accent type was H* – a total of 625 constituents were annotated with a H*. The number of the H* variations (i.e., including the constituents in which a delayed peak and/or downstepping was additionally identified) added up to 1,160 constituents, which took up approximately 73% of all accented constituents and 47% of all constituents overall. Variations of the L+H* pitch accent accounted for approximately 14% (228 constituents) and variations of the L* accent accounted for 12% (183 constituents) out of all accented constituents. The least common pitch accents were L*+H (16 constituents) and H+!H* (1 constituent).

Figure 7

Number of constituents without pitch accent annotation and with different accent types.

Figure 8 illustrates time-normalized average f0 contours for the three most common main accent types, i.e., variations due to a delayed peak and downstepping are combined into a single category. These were obtained from f0 measurements at 10 equidistant points on each constituent. Averages of these measurements, as well as error bars representing standard errors, appear in Figure 8 for each constituent and focus condition by main accent type. Average contours are clearly distinct for the three accent types H* (and its variations), L* (and its variations) and L+H* (and its variations), as well as consistent across constituents, with H*-accents showing a small peak followed by a slight fall, L* accents displaying a dip in f0 and L+H* accents showing a low turning point (L+) followed by a rise to a peak (H*) followed by a small fall. The difference between the H* contours and the “no-accent” contours was less than prominent. Here, differences in perceived prominence leading to the respective classification (cf. section 2.5) may not be reflected in average f0 contours. Finally, Figure 8 illustrates that average contours for all constituents and accent types were consistent across focus conditions, further suggesting that annotations reflect prosodic realizations rather than experimental conditions as such. Instead, some accents were never observed in certain experimental conditions – for example, no L+H* accent was observed for objects in the given conditions – i.e., SF and VF.

Figure 8

Averaged f0 contours of subjects, verbs and objects annotated with three most common pitch accents (the top three rows of panels) and averaged f0 contours of constituents with no accent (bottom row of panels) in different focus conditions.

To directly illustrate the correlation between the frequency of accent types and experimental conditions, Figure 9 shows the occurrences of each main pitch accent type divided by focus condition and constituent. The most noticeable pattern was the high number of unaccented constituents (labeled “No Accent”) in the given conditions across the constituents. It is also noteworthy that, while the H* pitch accent is the dominant type across the conditions, verbs with BF and VF are annotated with L* more frequently than subjects and objects in any condition. In addition, the L+H* accent was rare on verbs and objects, particularly in given conditions, but appeared relatively frequently on subject constituents in all conditions.

Figure 9

Number of constituents without annotated pitch accents and with different accent types on subjects, verbs and objects by focus conditions.

The first GLMM examined the likelihood of pitch accent annotation (vs. no accent) depending on location and focus condition (see Tables 15 and 16 in the Supplementary Materials). Recall that focus was re-coded for the analyses of pitch accents to reflect the information status of the individual constituent as being in broad focus (BF), narrow focus (NF) or given (GV) rather than reflecting the information structure of the whole utterance (BF, SF, VF, OF). The results showed significant main effects of focus and constituents: Constituents with NF were significantly more likely to be annotated as accented than constituents with BF, which in turn were more likely to be accented than given constituents. The low probability of pitch accent annotation for the given constituents corresponds to the high frequency of unaccented given constituents shown in Figure 9. Comparing the different constituents, subjects were significantly more likely to be accented than verbs, which were more likely to be accented than objects.

Focusing on the accented constituents in Figure 9, it appears that the majority of them was annotated with a H* variation, while far fewer constituents were annotated with a different type of pitch accent, regardless of the focus conditions and for all three constituents. The second GLMM therefore examined the probability of H* annotation compared to all other pitch accent types, excluding the unaccented constituents (see Tables 17 and 18 in the Supplementary Materials). Figure 10 shows the results of the inverse calculation of the estimates of the fixed effects in the model (specified in the logit scale), with higher values indicating more frequent/probable H* accents than lower values. The interaction between Focus and Constituent was significant, and the results of the multiple comparisons using the Tukey test are indicated by the compact letter display. The results of the second GLMM showed that, overall, accented constituents showed a probability of H* annotation higher than 50% across the focus conditions and locations. The results of the multiple comparisons between the levels of Focus and Constituent showed that narrow-focused verbs were significantly less likely to be annotated with a H* (‘a’) than given verbs (“bcd”) or objects in any focus condition (‘d’ or ‘cd’). Moreover, objects in any focus condition were more likely to be annotated with H* accents than broad-focused subjects (‘ab’) or given subjects (‘ab’). All other combinations of focus and location did not differ significantly from each other, suggesting an overall high probability of H* accents.

Figure 10

Probability of H* pitch accent annotation in different focus and location conditions.

3.4. Interim summary of the results of the pitch accent analysis

The pitch accent analysis showed that the presence of narrow focus led to higher probability of the focused constituents being annotated as accented, compared to broad focus and given constituents. It also showed the prevalence of H* accent under the presence of broad or narrow focus in the variety of Canadian English examined in the current study. The average f0 contours in different focus conditions and constituents suggest that the f0 shapes differ between the broad pitch accent categories such as H* and L+H*, although further research is needed to evaluate how the different types of focus map onto the different f0 shapes. Overall, the hypotheses in H2 (see 1.5) were partially supported: narrow-focused constituents were most frequently annotated as H*, which was far more frequent than L+H* across all conditions. In addition, while given constituents were less likely to be annotated as accented than broad-focused constituents, L* accents were not consistently associated with the given, accented constituents.