F0 Peak Research Articles

Alignment of f0 peak in different pitch accent types affects perception of metrical stress

In intonation languages, pitch accents are associated with stressed syllables, therefore accentuation is a sufficient cue to the position of metrical stress in perception. This paper investigates how stress perception in German is affected by different pitch accent types (with different f0 alignments). Experiment 1 showed more errors in stress identification when f0 peaks and stressed syllables were not aligned – despite phonological association of pitch accent and stressed syllable. Erroneous responses revealed a response bias towards the syllable with the f0 peak. In a visual-world eye-tracking study (Experiment 2), listeners fixated a stress competitor with initial stress more when the spoken target, which had penultimate stress, was realized with an early-peak accent (f0 peak preceding stressed syllable), compared to a condition with the f0 peak on the stressed syllable. Hence, high-pitched unstressed syllables are temporarily interpreted as stressed – a process directly affecting lexical activation. To investigate whether this stress competitor activation is guided by the frequent co-occurrence of high f0 and lexical stress, Experiment 3 increased the frequency of low-pitched stressed syllables in the immediate input. The effect of intonation on competitor fixations disappeared. Our findings are discussed with respect to a frequency-based mechanism and their implications for the nature of f0 processing.

How to pronounce a low tone: A lesson from Kaifeng Mandarin

A multi-speaker acoustic study on citation tones in Kaifeng Mandarin, referred to as LH, HL, H and L, shows that L is realized as three different subtypes by different speakers, i.e. dipping, falling and falling with lengthening, while generally being longer than the other three tones and frequently spoken with creaky voice in part of the vowel. This inter-speaker variation is reflected in the different transcriptions of Kaifeng L that have been given in the literature. We argue that a L-tone is intrinsically less salient than a H-tone, due to a lack of phonetic space in the low pitch range as well as to a potential ambiguity between contextual low pitch around f0 peaks and low pitch due to L-tones, and thus more likely to be enhanced.

Effects of formant proximity and language experience on subcortical neural encoding of vowels in adulthood

Formant frequency convergence (or “focalization”) and linguistic experience interact to shape the perception of vowels in adulthood. Here, we provide evidence of the effects of formant proximities and language experience at subcortical levels of the auditory pathway. Using a passive oddball/reversed oddball paradigm, the frequency-following response (FFR) in the auditory brainstem was elicited in sixteen healthy monolingual English speakers by a less-focal/English prototypic /u/ and a more-focal/French prototypic /u/. We examined the FFR as a function of stimulus type (English vs. French prototype) and condition (Standard vs. Deviant). A cross-correlation analysis revealed higher overall similarity between the FFR and evoking stimulus for the English prototype than the French prototype, suggesting an effect of language experience. Yet, deviants exhibited higher correlational values than standards. This effect was largely driven by the French prototype, suggesting an influence of focalization. A subsequent Fourier analysis revealed an effect of stimulus type at the f0 peak, whereas only a condition effect was observed at the first harmonic peak. The latter effect was largely driven by the French prototype. Altogether, these findings suggest that subcortical encoding of vowels in adulthood is influenced by a complex interplay between formant proximities and long-term linguistic experience.

Patterns of prominence, phrasing and tonal events in Spanish news reading: An illustrative case study

The present study examines the patterns in stress, phrasing and intonation found in a Spanish corpus of news read by broadcasters to describe the prosodic strategies that can be considered as genre-distinguishing features. Results indicate that, firstly, the main stress modifications concern the upgrading of unstressed syllables to accented ones, the stress shift to mark word-initial boundaries and the maintenance of adjacent stresses. Secondly, the special features related to phrasing are unexpected pauses, which enhance the prosodic units that offer new information, and the prosodic marking of initial edges of groups with the aim of capturing the listener’s attention. Finally, the most relevant tonal events that identify the typical chanting of broadcasters are a recurrent use of rises whose f0 peak coincides with the stressed syllable, a variety of non-falling pitch movements signalling intermediate phrasing, and the use of rising-falling pitch movements to signal ends. All the described prosodic and tonal strategies contribute to obtaining an emphatic style in news reading and are representative of a prosodically marked genre.

Differentiating infant cry from non-cry vocalizations based on perception of negativity and acoustic features

This study seeks to determine how human listeners discriminate cry vs. non-cry sounds by investigating acoustic factors that may contribute to the perception of negativity in infant vocalizations (e.g., cry, whine, and vowel-like sounds). The assumption is that identification of cry is self-evident; therefore, there has been no attempt to systematically differentiate cry from non-cry vocalizations. Twelve exemplars each of cry, whine, and vowel-like sound segments (36 total) were selected from archival audio recordings of infant vocalizations. Categories were selected from expert-judged audio signals of vocal development. Adult listeners identified each utterance as either cry, whine, or vowel-like sound as quickly and accurately as possible. They also judged the extent of negativity of each utterance. Acoustic features of each utterance were analyzed in association with the categories and degrees of negativity. Results suggest a continuum of negativity from cries (most negative) to vowel-like sounds (least negative), and that acoustic variables are gradated across the negativity continuum. However, preliminary results suggest that peak F0, peak RMS, and spectral slope best differentiate the categories.

Integrating the discreteness and continuity of intonational categories

It has already been observed that there is no one-to-one mapping between intonational categories and the pragmatic functions they are used to express. For instance, in German a particular pitch accent (L+H∗) is often used to express contrastive (corrective) focus, but neither is the use of this pitch accent confined to this function nor is this the only pitch accent used to express it. In particular, there are considerable differences across speakers in the use of pitch accents and the functions they express. In this paper we look at the phonetic parameters that are characteristic of each of these pitch accents (f0 peak alignment, tonal onglide and target height) and observe a striking similarity across speakers: All speakers modulate each parameter in the same direction, e.g. the f0 peak is aligned later for contrastive focus than for narrow focus. Whereas for some speakers this is transcribed as two different pitch accents (L+H∗ vs. H∗), for others it is not, and the peak alignment is treated as phonetic variation within one accent type (H∗). To capture both the differences and similarities in intonation, we therefore argue for an integrated analysis of the discrete phonological pitch accents and the modulation of continuous phonetic parameters that characterise them.

On the role of horizontal wind shears in the generation of F0.5 layers over the dip equatorial location of Thiruvananthapuram: A numerical simulation study

A numerical simulation is carried out to estimate the rate of convergence of ionization required to produce a F0.5 layer with peak plasma frequency (foF0.5) of 3.2MHz from three different background layer densities, over Thiruvananthapuram (8.5°N; 77°E; dip latitude ~ 0.5°N), a dip equatorial station in India. Further the simulation study is extended to understand the convergences required by considering the seasonal mean peak F0.5 layer frequencies also. One possible mechanism by which this convergence can be produced is by a horizontal shear in the meridional wind. The corresponding shears required to generate the layer with the above convergence conditions are estimated. It is found that gravity waves are capable of generating wind shears, leading to the pooling of ionization and the generation of the layer over the dip equator. A meridional wind with the gravity wave induced wind shear is numerically estimated. Finally, the short scale gravity waves of periods around 3–23min have been inferred to be more efficient in generating the wind shear when compared to large scale horizontal waves leading to the generation of F0.5 layer.

Interaction of jaw displacement and F0 peak in syllables produced with contrastive emphasis

Interaction of jaw displacement and F0 peak in syllables produced with contrastive emphasis

Bidirectional prosodic effects of code-switching in Spanish-Basque bilinguals

This study investigates the prosody of code-switching in Spanish-Basque bilinguals, which has not been previously documented. Peninsular Spanish and Basque have several prosodic differences, including peak alignment in pitch accents. Spanish has delayed peaks (Estebas Plana & Prieto (2008)), while Basque has early peaks (Elordieta & Hualde (2015)). The current study investigates whether code-switched words are conditioned by prosodic position and whether the peak alignment and f0 maximum of a pitch accent differ between monolingual context (Spanish only) and code-switched contexts. Bilinguals (aged 21-31) from a Basque-dominant region (Lekeitio, n = 3) and a Spanish-dominant region (Bilbao, n = 4) participated in the present study. The data was coded for the following predictor variables: prosodic position, peak alignment, and f0 maximum in pitch accents. Results reveal that code-switches occur almost equally in phrase-medial and final positions. For peak alignment, Lekeitio speakers produced early peaks in both code-switching contexts (Spanish-Basque, Basque-Spanish), which matches monolingual norms for Lekeitio varieties of Spanish and Basque. However, Spanish-dominant speakers also produced early peaks in both code-switching contexts, despite delayed peak norms for Peninsular Spanish. Finally, preliminary results reveal greater f0 during code-switching contexts for Lekeitio speakers only. Further results and implications will be discussed.

Acoustic and articulatory measures of prosodic convergence in a cooperative maze navigation task

Convergence effects have been found in many aspects of communication between speakers in conversation. This study examines how phonetic properties of each speaker’s prosodic structure differ before, during and after participating in a cooperative maze task. Using two NDI electromagnetic articulatory tracking systems simultaneously, we recorded speakers of American English in dyads (one male dyad & one female dyad). Acoustic measurements included: 1) sentence durations, 2) phrase-final lengthening, 3) occurrence frequency of sentence-final boundary tones (percentage H%), and 4) peak F0 values in sentence-final words. Articulatory boundary strength measures for word-final consonant(s) articulations included: 1) movement durations, 2) displacement, and 3) time-to-peak velocity in phrase-medial and phrase-final positions. Speakers exhibited distinct phonetic patterns before the cooperative maze task. However, conversing speakers showed convergence effects in prosodic boundary strength, choice of boundary tone...

The Importance of a Distributional Approach to Categoriality in Autosegmental-Metrical Accounts of Intonation

When annotating a speech signal using an autosegmental-metrical model of intonation, transcribers associate portions of the F0 contour with labels from a finite inventory of tonal categories. In the models we are concerned with here, these categories have the status of phonological units (phonological form), bridging the intrinsic variability of the speech signal (substance) with the intrinsic fuzziness of post-lexical function (meaning). This, together with the relatively small size of the label inventory, precludes a one-to-one relationship between form and substance, and/or between form and function. A Neapolitan Italian corpus of read speech is used to investigate the distributional properties of two pitch accents that have been studied extensively with respect to substance (the alignment of F0 peaks) and meaning (sentence modality). Although there is a general consensus that peaks in this variety are aligned earlier in declaratives than in interrogatives, evidence is provided of contexts in which the converse is true, i.e., in which interrogative peaks are even earlier than their declarative counterparts. In this respect, interrogatives have a richer internal structure than declaratives. We argue that differences in how variably a prosodic category is encoded can be dealt with in an intonation transcription system, as long as this system relates phonological form (the choice of pitch accent in this case) both to phonetic substance and to meaning in a transparent way.

Tonal association in Tashlhiyt Berber: evidence from polar questions and contrastive statements

The placement of F0 peaks in Tashlhiyt Berber is highly variable, both within and across speakers, even across repetitions of the same target sentence. We show that peak placement is determined by a number of competing factors: in addition to a general tendency for the peak to be placed on the rightmost syllable – a tendency that is stronger in questions than in statements – the peak is attracted to the syllable with the most sonorous nucleus and preferentially to heavy syllables. Moreover, in words consisting entirely of obstruents, there are three possible intonation patterns: no F0 peak at all, an anticipated peak (before the target word) or a peak on a vocoid between two obstruents. The F0 peak is analysed phonologically as a H tone that is either associated with a postlexically determined syllable or, if the syllable is not tone-bearing, aligned with the edge of the larger domain.

Brainstem encoding of speech in normal-hearing individuals with absent acoustic reflex

The acoustic reflex test is an important tool for identifying auditory disorder from the middle ear to the superior olivary complex. Absence of acoustic reflexes is the early sign of many auditory disorders. Absence of acoustic reflex with normal hearing sensitivity may be an early sign of auditory neuropathy with poor encoding of speech at initial stage. Speech auditory brainstem response was recorded with /da/ (40 ms) stimuli in two groups of patients. The control group contained normal-hearing participants with presence of acoustic reflex, whereas the experimental group contained normal-hearing participants with absent acoustic reflexes. The peak latency, amplitude, and F0 and F1 mean amplitude were analyzed in both groups. MANOVA showed no significant difference in any parameter between the control and experimental group. Results of the current study showed that absence of acoustic reflexes in normal-hearing patients without auditory complaint is not sufficient by itself to diagnose the existence of auditory neuropathy. This study also highlighted that normal-hearing patients with absence of acoustic reflex have similar brainstem encoding of speech as that of patients with acoustic reflex.

When pitch Accents Encode Speaker Commitment: Evidence from French Intonation.

Recent studies on a variety of languages have shown that a speaker's commitment to the propositional content of his or her utterance can be encoded, among other strategies, by pitch accent types. Since prior research mainly relied on lexical-stress languages, our understanding of how speakers of a non-lexical-stress language encode speaker commitment is limited. This paper explores the contribution of the last pitch accent of an intonation phrase to convey speaker commitment in French, a language that has stress at the phrasal level as well as a restricted set of pitch accents. In a production experiment, participants had to produce sentences in two pragmatic contexts: unbiased questions (the speaker had no particular belief with respect to the expected answer) and negatively biased questions (the speaker believed the proposition to be false). Results revealed that negatively biased questions consistently exhibited an additional unaccented F0 peak in the preaccentual syllable (an H+!H* pitch accent) while unbiased questions were often realized with a rising pattern across the accented syllable (an H* pitch accent). These results provide evidence that pitch accent types in French can signal the speaker's belief about the certainty of the proposition expressed in French. It also has implications for the phonological model of French intonation.

Fundamental frequency movements in one-word imperatives

F0 contours in Spanish declarative and imperative sentences have traditionally been described as identical and it has not been until recently that several phonetic variables have been identified as markers of imperativity. These include higher overall F0s, early peak alignments in pre-nuclear pitch-accents, upstepped nuclear pitch-accents and marginal use of high boundary tones. Since previous analyses have concentrated on utterances with multiple pitch-accents, not much is know about productions with just one word. This study focuses on one-word utterances given the tendency of imperatives to be short and taking into account that some of the aforementioned phonetic markers cannot be used with a sole pitch-accent. The analysis of 117 declarative sentences and 256 imperatives produced by eight Spanish speakers demonstrated that in cases where declaratives and imperatives share the same contour (L+>H*L%), the latter tend to have higher F0 peaks (Wilcoxon signed-rank test; p<0.000). Besides, 32.4% of the imperatives showed F0 contours ending in high boundary tones, a marker not used in declaratives and only marginally found in imperatives with multiple pitch-accents. Current findings suggest that when segmental material limits F0 movements, speakers look for alternative phonetic strategies to distinguish between declaratives and imperatives.

Acoustic evidence for diachronic sound change in Korean prosody: A comparative study of the Seoul and South Kyungsang dialects

This paper examined the acoustic properties of the pitch accent of South Kyungsang Korean, focusing on generational differences. Kyungsang Korean has lexical pitch accents, whereas standard Seoul Korean does not. However, whether the pitch accents are maintained by younger Kyungsang speakers is questionable given the influence of Seoul Korean. Through comparisons between older and younger speakers and between Seoul and South Kyungsang speakers, this study tested if and how sound change occurs in the pitch accent system of the regional dialect, and if the prosody of Kyungsang Korean shifts towards that of non-tonal Seoul Korean. We examined F0 scaling and alignment of pitch accents for the data collected from 40 female Korean speakers (10 younger and 10 older speakers each for Seoul and South Kyungsang dialects). Clear acoustic differences between generations provided evidence for diachronic sound change in the lexical pitch accent of South Kyungsang Korean. First, the differences in F0 scaling and alignment across accent contrasts are less distinct for younger Kyungsang speakers than for older speakers. Second, the F0 peak occurs later for younger Kyungsang speakers across all accent classes, resulting in a final rising accent pattern in disyllables similar to Seoul Korean. Third, despite the similarity with Seoul Korean, results from longer words revealed that Kyungsang Korean is still distinct from Seoul in terms of its maintenance of the lexical pitch accent. Based on these findings, we conclude that the sound change in lexical pitch accent is in progress by satisfying the prosodic properties of both Seoul and South Kyungsang Korean.

The continuous or categorical effects for HH vs. HL and HH vs. LH in lexical pitch accent contrasts of Korean

The current research examines whether pitch contour shapes in North Kyungsang pitch accent contrasts provide a phonetic dimension for phonological discreteness in a mimicry task. Two pitch accent continua resynthesized were created for HH vs. HL and HH vs. LH. To confirm a phonetic dimension for accounting for pitch accent categories in North Kyungsang Korean, the mimicries of speakers of two dialects (i.e., North Kyungsang & South Cholla) were compared. One of the findings showed that, for North Kyungsang speakers, the range of mean f0 peak times was a phonetic dimension undergoing a continuous shift within a stimulus continuum for both HH vs. HL and HH vs. LH. On the other hand, for South Cholla speakers, there were no apparent shifts around categorical boundaries for either HH vs. HL or HH vs. LH. Regarding individual mimicries on f0 peak timing, there are many variations. For HH vs. LH, three North Kyungsang speakers showed a discrete pattern reflecting a shift in phonological categories, but for HH vs. HL, there was no such distinction showing a categorical shift, though there were statistically significant differences for two speakers. Interestingly, one of the North Kyungsang speakers showed a continuous phonetic dimension for both HH vs. HL and HH vs. LH. Lastly, the f0 valley timing did not exhibit a discrete or gradient phonetic dimension for speakers of either dialect. On the basis of these results, what is interesting is that the tonal target such as high tone in North Kyungsang pitch accent categories within the autosegmental-metrical (AM) theory may be realized within individual cognitive systems for representing the interaction of perception and production.

Sentence planning and f0 scaling in Wenzhou Chinese

This study investigated the effect of constituent length and syntactic complexity on f0 pre-planning in Wenzhou Chinese. We compared the scaling of constituent-initial f0 peaks in sentences with identical syntactic structure (SVO) and different constituent lengths (1–3 words in the subject/object) to determine whether f0 pre-planning spans over the entire utterance or is confined locally to sub-constituents. Furthermore, different types of embedded clauses with the same length were tested to assess the influence of syntactic structures on sentential f0 scaling.Results showed that initial f0 peak within the subject or object varied mainly as a function of the length of the respective constituent, with only subtle influence from their respective other constituent, suggesting that f0 scaling in Wenzhou Chinese is determined primarily by the length of the target constituent. The scope of planning, however, cannot be categorically confined to the sub-constituents and instead, is graded over the whole utterance with strong activation over the subject phrase and weak activation over the object phrase. For sentences with embedded clauses, there was a significantly steeper f0 peak/valley drop across a clause boundary than that across a phrasal boundary, suggesting a tight mapping between major syntactic structure and prosodic planning.

Quantitative Analysis of Digital Videokymography: A Preliminary Study on Age- and Gender-Related Difference of Vocal Fold Vibration in Normal Speakers

Kymography is an effective method for assessing temporal patterns of vocal fold vibrations. Because kymographic data for a number of normal speakers based on high-speed digital imaging (HSDI) were limited in the literature, this prospective study was conducted to provide normative kymographic HSDI data and clarify gender- and age-related normal variations. Vocally healthy adults were divided into young (≤35years) and elderly groups (≥65years). Kymograms were recomposed from HSDI data at the midglottal level, and kymographic parameters were analyzed quantitatively. Then gender- and age-related differences were evaluated. A total of 26 young subjects (9 men and 17 women, mean age: 27years) and 20 elderly subjects (8 men and 12 women, mean age: 73years) were investigated. Obtained data generally matched the values in the literature. Slight asymmetry was seen in all groups, with the elderly subjects having more evident asymmetry than the young subjects. Most of the kymographic parameters showed a negative correlation with fundamental frequency (F0), whereas the open quotient displayed a positive correlation with F0. There were significant intergroup differences in F0, amplitude and lateral peak at a speaking F0. The present quantitative findings generally matched the qualitative kymographic data reported in the literature. When judging whether a vibratory pattern is normal or pathological, both gender and age should be taken into account, because gender- and age-related variations of symmetry, F0, and phase were frequently observed in the present study.

Mechanism of Disyllabic Tonal Reduction in Taiwan Mandarin.

This study was designed to test the hypothesis that time pressure is a direct cause of tonal reduction in Taiwan Mandarin. Tonal reduction refers to the phenomenon of the tones of a disyllabic unit being contracted into a monosyllabic unit. An experiment was carried out in which six native Taiwan Mandarin male speakers produced sentences containing disyllabic compound words /ma/+/ma/ with varying tonal combinations at different speech rates. Analyses indicated that increasing time pressure led to severe tonal reductions. Articulatory effort, measured by the slope of F0 peak velocity of unidirectional movement over F0 movement amplitude, is insufficient to compensate for duration-dependent undershoot (in particular, when time pressure exceeds certain thresholds). Mechanisms of tonal reduction were further examined by comparing F0 velocity profiles against the Edge-in model, a rule-based phonological model. Results showed that the residual tonal variants in contracted syllables are gradient rather than categorical--as duration is shortened, the movement towards the desired targets is gradually curtailed.