Modal Vowels Research Articles

Tense voice without the high f0: the case of glottalized vowels in Zongozotla Totonac

Prototypical creaky voice involves increased glottal constriction, lower periodicity, and lower f0. Keating et al. (2015, Proc. ICPhS) argue that other kinds of creaky voice manifest only some of these properties. For example, “tense voice” is constricted but has neither a low nor irregular f0. Although tense voice is usually produced with a high f0, the aforementioned authors suggest that tense voice can also occur with non-high f0. In this study, we argue that glottalized (also known as “laryngealized”;) vowels of Zongozotla Totonac qualify as such: they are produced with tense voice but with non-high f0. Zongozotla Totonac is a Totonac-Tepehua language spoken in the municipality of Zongozotla, Puebla, Mexico. We recorded eight speakers producing nine word pairs that contrast in terms of modal versus glottalized vowels. Compared to modal vowels, glottalized vowels show increased constriction, as indexed by lower spectral tilt and weaker voicing. However, glottalized and modal vowels do not differ in terms of f0 or periodicity. Taken together, the results suggest that glottalized vowels are produced with tense voice, for which the increase in constriction is criterial. This analysis has implications for understanding sound change in Totonac as well as for the taxonomy of creaky voice subtypes.

Phonetic realization of vowel length and glottalization in Todos Santos Mam

Mam (Guatemala: Mayan) is described as having a vowel length contrast, as well as a laryngeal contrast between glottalized and modal vowels [England 32–36 (1983)]. Glottalized vowels are described as having a falling pitch contour and being longer relative to their modal counterparts (ibid.). However, there are no phonetic studies explicitly confirming this. In particular, the Todos Santos dialect has received almost no phonetic investigation, and the presence and realization of the length and laryngeal contrasts is not well-established. This study is one of the first phonetic studies of vowel length and glottalization in Todos Santos Mam. The authors collected data of one native speaker reading a list of words varying in vowel quality. We find evidence for both a length contrast and laryngeal contrast. For the length contrast, short vowels are significantly shorter in duration and lowered relative to long vowels. For the laryngeal contrast, glottalized vowels are found to have a falling pitch contour, while modal vowels have level/rising pitch. In addition, a lengthening effect was found such that short glottalized vowels are longer than their modal counterparts, but it is unclear whether the same effect is present for long glottalized vowels.

Nuer Tonal inventory

The tonal system of Nuer has been a matter of much uncertainty. Here we present empirical evidence in favor of a three toneme system with some typologically rare features. One of them is an intriguing case of allotony based on the phonation of the vowel: the High toneme has a falling allotone over modal vowels. Moreover, the Rising toneme has four allotones: a rising, a mid, a low and a falling allotone. The falling allotone of the Rising toneme also occurs only on modal vowels in specific contexts. We suggest that some of the allotonic variation is motivated by tonal contour simplification. We also point out the role of free variation in some of the allotonic alternations, and the constraints that put limits on the free variation between allotones.

Distinguishing breathy consonants and vowels in Gujarati

Abstract Across languages, the acoustic and articulatory correlates of breathiness are similar whether they are associated with consonants or with vowels. This raises the question of whether breathy consonants are confusable with breathy vowels in languages in which a phonemically breathy vowel contrasts with a phonemically modal vowel that follows a breathy-aspirated consonant, e. g. Gujarati /ba̤ɾ/ ‘outside’ vs. /bʱaɾ/ ‘burden’, respectively. We investigate the perception of a minimal triplet of Gujarati words, with a breathy vowel vs. a breathy consonant vs. an all-modal sequence, via three tasks: free-sort, AX discrimination, and picture-matching identification. Results across the three tasks indicate that breathiness is indeed confusable across the association types. Specifically, while listeners do recognize the stronger breathiness in vowels following breathy consonants, they are not necessarily able to determine whether that breathiness is associated with the vowel or the consonant. Furthermore, they do not reliably recognize the subtler breathiness of breathy vowels, which often indicates that they are the same as or an acceptable realization of an all-modal sequence (/baɾ/ ‘twelve’). This suggests a potential perceptual merger in Gujarati, despite previously-reported evidence of a robust three-way contrast in production.

The role of vowel length and glottalization in German learners’ perception of the English coda stop voicing contrast

In German, the voicing contrast in word-final stops is neutralized towards the voiceless sound. We tested how German learners of English use in perception two phonetic cues to this contrast in English: the duration of the vowel preceding the stop and the partial glottalization of this vowel. While a longer vowel cues the voiced sound of the contrast, glottalization enhances the voiceless sound, which should be ‘easy’ for learners as word-finally it is the default in German. We asked whether cueing the ‘easy’ sound would nevertheless affect learners’ word identification. Learners categorized two English minimal pairs along vowel duration continua with either a fully modal vowel or the last 25% of the vowel glottalized. Learners gave more voiced-stop responses as vowel duration increased. They also used glottalization by giving fewer voiced-stop responses for the glottalized continua. A second experiment demonstrated that the glottalization was not merely perceived as a change in the vowel+closure duration ratio. When the glottalized portion of the vowels was set to silence learners gave even fewer voiced-stop responses than in the glottalized condition. Results suggest that learners can use a phonetic cue to a second language sound contrast even if it enhances the familiar ‘easy’ sound.

Acoustic properties of vowels in Upper Necaxa Totonac

Upper Necaxa Totonac is a Totonacan language spoken in the Necaxa River valley in the Sierra Norte of Puebla State, Mexico. While the Totonacan languages historically have three phonemic vowel qualities, the Upper Necaxa system consists of five vowels that contrast length and laryngealization. With acoustic data from six native speakers from the Totonacan communities of Patla and Chicontla, we explore the phonetic properties of vowels with respect to the first and second formant frequencies, quantity (duration), vowel phonation (modal vs. laryngeal), and stress. The data indicate that long, short, modal and laryngeal vowels occupy a similar formant space and that duration is the primary phonetic correlate of phonemic vowel length. A shift in vowel quality and an increase in duration and pitch were shown to be the acoustic characteristics of stress. The study provides a first acoustic analysis of vowels in Upper Necaxa, and contributes to typological descriptions of the properties of vowels connected with quality, quantity, stress, and phonation.

Isthmus Zapotec vowel formants

This paper addresses several questions regarding the acoustic properties of Isthmus Zapotec vowels. Based on earlier recordings of a female, mother-tongue speaker of the language, average formant frequencies for each of the five phonemic vowels are determined for this speaker. I then look at differences in formant frequencies between stressed and unstressed modal vowels. Finally, I compare modal, laryngealized and checked productions of the vowels, to see if there are systematic differences between these three phonation types.

Phonation type in vowels of heritage and native Gujarati speakers

Gujarati, an Indo-Aryan language, contrasts phonation type in vowels: [baɾ] ‘twelve’ and [baɾ] ‘outside’ (Pandit, 1957) and the current study looked at Gujarati vowels using acoustic and electroglottographic (EGG) analyses. The participants were native and heritage Gujarati speakers. Heritage speakers were born in Canada or arrived in Canada before seven years of age and learned Gujarati as their first language. Due to limited access to their first language, such as listening more than speaking the language and using Gujarati exclusively at home, it was expected that there might not be a significant difference between the heritage speakers’ breathy and modal vowel productions. This study determined if the acoustic and EGG parameters that differentiate breathy from modal vowels were the same or different for both speaker groups. Some of the parameters used to distinguish phonation type were H1-H2, H1-A1 ('A1' refers to amplitude of the first formant), harmonic-to-noise ratio, and contact quotient. Measure...

Evaluating acoustic measurements of creaky voice: A Vietnamese case study

It has been proposed that there are two broad categories of creaky voice (CV), laryngealized and aperiodic. Moreover, several subdivisions have been proposed for both categories (Keating & Garellek, 2015), and various combinations of acoustic properties have been associated with each. It remains unclear, however, how to determine which type of CV a language has and which acoustic measurements to rely on. We address this problem with two rising tones in Vietnamese differing in phonation. All of the phonation measurements we tested with ANOVA were statistically significant (p < .01) in the distinction between the two tones, and thus inconclusive as to the type of CV. We propose that an additional binary logistic regression analysis be applied to the various measurements to determine the extent to which each one contributes to classifying creaky vs. modal vowels; and this, in turn, can inform us about the nature of the CV in the language. Specifically in Vietnameses, we found that HNR yields the strongest classification result (84%); the others were closer to chance (58–68%). We can thus conclude that the CV used in Vietnamese is the aperiodic type, as evidenced by the role of irregular F0 as opposed to the other phonation properties.

Automatic detection of breathy voiced vowels in Gujarati speech

This paper proposes a method for automatic detection of breathy voiced vowels in continuous Gujarati speech. As breathy voice is a specific phonetic feature predominantly present in Gujarati among Indian languages, it can be used for identifying Gujarati language. The objective of this paper is to differentiate breathy voiced vowels from modal voiced vowels based on loudness measure. Excitation source characteristics represented by loudness measure are used for differentiating the voice quality. In the proposed method, initially vowel regions in continuous speech are determined by using the knowledge of vowel onset points and epochs. Later, hypothesized vowel segments are classified by using loudness measure. Performance of the proposed method is evaluated on Gujarati speech utterances containing around 47 breathy and 192 modal vowels spoken by 5 male and 5 female speakers. Classification of vowels into breathy or modal voice is achieved with an accuracy of around 94 %.

The phonetics of contrastive phonation in Gujarati

The current study examines (near-)minimal pairs of breathy and modal phonation produced by ten native speakers of Gujarati in connected speech, across different vowel qualities and separated by nine equal timepoints of vowel duration. The results identify five spectral measures (i.e. H1–H2, H2–H4, H1–A1, H1–A2, H1–A3), four noise measures (i.e. cepstral peak prominence and three measures of harmonics-to-noise ratio), and one electroglottographic measure (i.e. CQ) as reliable indicators of breathy phonation, revealing a considerably larger inventory of cues to breathy phonation than what had previously been reported for the language. Furthermore, while the spectral measures are consistently distinct for breathy and modal vowels when averaging across timepoints, the efficacy of the four noise measures in distinguishing phonation categories is localized to the midpoint of the vowel's duration. This indicates that the magnitude of breathiness, especially in terms of aperiodicity, changes as a function of time. The current study supports that breathy voice in Gujarati is a dynamic, multidimensional feature, surfacing through multiple acoustic cues that are potentially relevant to the listener.

The Perception of Pathologically-disordered Phonation by Gujarati, English, and Spanish Listeners

This study investigates the influence of linguistic experience on the perception of pathologically-disordered voices using 18 listeners of American English, which has allophonic breathiness, 12 listeners of Gujarati, which contrasts breathy and modal vowels, and 18 listeners of Spanish, which has neither allophonic nor phonemic breathiness. Listeners rated the similarity of pairs of pathologically-disordered voices. Multidimensional scaling was used to determine the properties that were most correlated with perception for each listener group. Results showed that Gujaratis' perception was correlated with the difference between the amplitude of the first (HI*) and second (H2*) harmonic (HI*-H2*), which is associated with the production of phonation in Gujarati. English listeners' judgments were correlated with the measure HI*-H2* and cepstral peak prominence, and Spanish listeners' judgments were correlated with HI*-H2 and HI*-AI* (the amplitude of the principal harmonic near the first formant). When compared to Esposito (2006), which asked the same listeners to rate the similarity of breathy and modal vowels from Mazatec, results showed that Gujarati listeners classified the pathologically-disordered stimuli in the same way that they classified the Mazatec stimuli, while English and Spanish listeners perceived the pathologically-disordered stimuli and the Mazatec stimuli in slightly different ways.

Contrastive breathiness on consonants and vowels.

While numerous languages exhibit contrastive breathy phonation either on consonants (e.g., Indic languages) or on vowels (e.g., Zapotec languages); very few languages preserve this contrast across both consonants and vowels. Two such languages are Gujarati and White Hmong. Given that breathiness on consonants is typically realized as a breathy-voiced release into the following vowel, how are the two types of breathiness distinguished in CV sequences, if at all? We examine acoustic and electroglottographic data collected from speakers of Gujarati and White Hmong to determine what properties reliably distinguish breathy and modal voice in potentially ambiguous CV sequences, and to explore the phonetic and phonological properties shared between these two genetically unrelated languages. Preliminary results from both languages are strikingly similar; modal vowels adjacent to breathy consonant releases strongly resemble phonemically breathy vowels, and only the exact timing and magnitude of the acoustic reflexes of breathiness phonetically distinguish the two sequences. Phonological evidence in the form of distributional constraints, however, can aid listeners of both languages in determining the source of breathiness: both languages prohibit the co-occurrence of breathy consonants and breathy vowels, and in White Hmong, tonal cues can also reveal the underlying phonation of an ambiguous CV sequence.

The effects of linguistic experience on the perception of phonation

This study investigates the role linguistic experience has on the perception of phonation and acoustic properties that correlate with this perception. Listeners from Gujarati (contrasts breathy versus modal vowels), Spanish (no breathiness) and English (allophonic breathiness) participated in: (1) a similarity-rating task, indicating the similarity of modal and/or breathy Mazatec vowels and (2) a free-sort task, sorting breathy and modal stimuli from many languages. Results showed that Gujaratis did better at distinguishing phonation in other languages/dialects and were more consistent. English listeners did no better than Spanish listeners, despite the allophonic breathiness in English. In terms of acoustic dimensions, results showed that Gujaratis relied on H1−H2 (amplitude of the first harmonic minus amplitude of the second harmonic), English listeners relied weakly on H1−H2 and cepstral peak prominence and Spanish listeners relied on H1−A1 (amplitude of first formant peak) and H1−H2. While it is not clear why Spanish listeners used H1−A1, we can speculate as to why all three groups of listeners used H1−H2. Cross-linguistically, H1−H2, which is correlated with the open quotient ( Holmberg, Hillman, Perkell, Guiod, & Goldman, 1995), is the most successful measure of phonation. Perhaps the reason is a perceptual one; open quotient differences might be more salient to listeners.

Breathy phonation in Gujarati: An acoustic and electroglottographic study.

Recent electroglottographic research on Gujarati [Khan (2009)] reveals that speakers consistently distinguish breathy and modal vowels (e.g., /bar/ “twelve” vs /bAr/ “outside;” capitalization represents breathiness) by both closed quotient and closing velocity. Despite this interspeaker uniformity measured at the voice source, the acoustic correlates of the contrast measured in the speech output vary considerably across speakers. While some speakers mark breathiness with a larger H1-H2 difference, others use lower periodicity (CPP) or greater changes in intensity (rms energy). It is unclear how breathy vowels are contrasted with modal vowels following breathy consonants (e.g., /bAr/ “outside” vs /Bar/ “burden”) or to what extent the preceding consonant manner can affect the spectral acoustics of the vowel (e.g., /pAr/ “mountain” vs /vAn/ “vehicle”). To better capture the variation in both vowel and consonant phonations, the current study examines acoustic and electroglottographic data collected from naturalistic productions of near-minimal sets from a larger pool of Gujarati speakers, using a wider range of vowel and consonant types. Preliminary results suggest that while all speakers distinguish phonation types in both consonants and vowels based on electroglottographic measures, the acoustic cues in the output are far more complex. [Work supported by NSF.]

Effects of native language on perception of the relative amplitudes of the first and second harmonics.

As an incidental result of previous studies of the perception of spectral slope, we found that Mandarin speakers were nearly twice as sensitive to changes in the amplitude of the first harmonic relative to the second (H1-H2) as are English speakers. Although two Mandarin tones are typically produced with characteristic changes in voice quality, Mandarin does not contrast phonation types directly. Thus, the observed difference between listener groups could be due to increased attention to overall source characteristics in speakers of tone languages (because F0=H1), or specifically to experience with voice quality differences apart from F0. To clarify this matter, we measured just-noticeable differences in H1-H2 for speakers of Gujarati, a non-tonal language that contrasts breathy and modal vowels in H1-H2, and for speakers of a language like Yoruba that contrasts tones but not phonation types. If increased sensitivity to H1-H2 differences is due to attention to H1, then just-noticeable differences for both groups should be smaller than those for English speakers. However, if perceptual experience specifically with the H1-H2 contrast is required, then Gujarati speakers, but not Yoruba speakers, should show increased sensitivity relative to English speakers. [Research supported by NIH and NSF.]

An acoustic and electroglottographic study of breathy phonation in Gujarati.

While it has long been established that breathy and modal vowels in Gujarati can be reliably distinguished based on the H1-H2 measure [Fischer-Jorgensen (1967); Bickley (1982)], and that Gujarati listeners attend solely to H1-H2 when distinguishing phonation types in Gujarati and in other languages [Bickley (1982); Esposito (2006)], new research [Khan and Thatte (2009)] suggests that in more casual speech styles, H1-H2 may play a smaller role in distinguishing breathy-modal minimal pairs. In such speech styles, additional acoustic measures (e.g., H1-A3, CPP, and rms energy) are more effective in distinguishing breathy and modal vowels for some speakers. To more closely examine the phonetics of breathy vowels in casual speech, the current study examines both acoustic and electroglottographic data collected from naturalistic productions of breathy-modal minimal pairs. Preliminary data suggest that while all speakers distinguish modal and breathy vowels, the strategies used by each speaker to produce the contrast vary considerably. [Work supported by NSF.]

The phonetics of contrastive phonation in Gujarati.

Gujarati is known for distinguishing breathy and modal phonation in both consonants and vowels [(Cardona and Suthar, 2003)], e.g., /ba:r/ “twelve” versus /Ba:r/ “burden” versus /bA:r/ “outside,” where uppercase represents breathiness. The current study investigates acoustic and glottographic properties of this three-way contrast. [Fischer-Jo/rgensen (1967)] and [Bickley (1982)] showed that the H1-H2 measure can reliably distinguish breathy and modal vowels, and [Esposito (2006)] further found that Gujarati listeners exclusively attend to H1-H2 to categorize audio samples from other languages, even when H1-H2 did not reliably distinguish contrastive voice quality in those languages. However, do other acoustic properties also distinguish breathiness in Gujarati? In addition what physiological differences underlie the acoustic differences? The current study tests the reliability of several phonetic measures (e.g., H1-H2, H1-A1, CPP, CQ, etc.) to distinguish 33 (near-) minimal sets contrasting breathy and modal segments in audio and electroglottographic data produced by both male and female Gujarati speakers. [Work supported by NSF].

The effects of linguistic experience on the perception of breathy phonation.

This study investigates the role linguistic experience has on the perception of phonation and the acoustic properties that correlate with this perception. Listeners from Gujarati (contrasts breathy versus modal vowels), Spanish (no breathiness), and English (allophonic breathiness) participated in two tasks. In the visual sort, subjects sorted breathy and modal vowels from a variety of languages into two groups based on perceived similarity of the talkers’ voices. In the multidimensional scaling task, listeners heard pairs of Mazatec vowels, and moved a slider to indicate perceived similarity of vowels in each pair. Results showed that judgments were more uniform across subjects who had breathy categories present in their native language and varied across subjects who lack a breathy category. Despite allophonic breathiness, English listeners did no better at distinguishing phonations than Spanish listeners. The perceived similarity among the stimuli correlated with measurable acoustic properties (H1‐H2, H...

The influence of creaky voice on formant frequency changes

When disguising their voice, women may tend to lower their fundamental frequency so as to imitate a male’s voice. This implies a lowered fundamental frequency on the one hand and the production of creaky voice or creak over large sequences on the other. For speaker identification which additionally relies on formant frequency comparison, it is therefore of interest if the production of creaky voice implies an additional modification of the vocal tract and consequently has an effect on formant frequencies. In the present study, the second and third formant of 750 creaky and modal vowels of five female and four male speakers were compared. As a main result, a sex-specific difference has been observed. Creaky vowels produced by women show a lower second formant as compared to the same vowels produced by the same speaker using modal phonation. Changes in the third formant during low creaky voice disguise by women and, more generally, the effect on male formant values, was found to be inconsistent.