Lower Formant Research Articles (Page 1)

This study examines how auditory spectral representations in the peripheral auditory system explain changes in vowel production under noisy conditions, especially when lower formants (F1 and F2) are masked. Ten adult male Japanese speakers produced sustained vowels /a/ and /i/ under quiet and noisy conditions involving three noise types (broadband, low-pass, and high-pass) at 75 and 85 dB. We analyzed vocal intensity and the amplitudes and frequencies of the F1 and F2. Auditory spectral representations, simulated using a loudness model, were used to estimate excitation patterns in the auditory periphery. Most noise conditions significantly increased vocal intensity and the amplitude of both formants. F1 frequency consistently shifted upward under high-intensity broadband noise, while F2 shifts depended on vowel and noise type, shifting upward for /a/ and downward for /i/. Some patterns could not be explained by power spectra alone. Instead, they were better accounted for by frequency-specific masking effects, reflected in overlapping excitation patterns in the auditory spectral representation. These overlaps indicated reduced self-audibility in specific frequency bands, triggering compensatory adjustments. The findings highlight how auditory masking influences speech production, supporting a perceptually grounded model of auditory-motor control in noisy environments.

Gender-affirming communication services are based on studies of speech produced and perceived by cisgender men and women. The current study examined the perception of gender and gender orientation (i.e., whether someone is cisgender or transgender) in the Palette of Voices, an openly available corpus of the speech of transgender and cisgender men, by cisgender heterosexual men (CHM) and cisgender heterosexual women (CHF), and a group of gender and sexuality expansive (GSE) listeners. We examined how both the acoustic characteristics of speech and listener identity affect gender and gender orientation categorization. Participants (n = 199) categorized the gender and gender orientation of 240 sentence productions produced by 20 male talkers in an online experiment, including tokens whose fundamental frequency (F0) and formant frequency scaling had been altered, and unmanipulated tokens. Consistent with previous research, productions with lower F0 and lower formant frequencies were more likely to be categorized as male than ones with higher F0s and formants. The weighting of these variables differed systematically across listener groups, with the GSE group weighting these variables less than the CHM and CHF groups when categorizing gender, but more when categorizing gender orientation. The relationship between the acoustic characteristics of a talker's speech and the categorization of their gender and gender orientation is highly variable across and within groups. The perception data and speech samples in this study are openly available. Suggestions are given for how they might be used to supplement existing gender-affirming communication services.

Chongqing dialect, having experienced the waves of ethnic migration, has given birth to distinctive linguistic features. Since the 1980s, academic research on the Chongqing dialect has gradually increased. However, most studies have only scratched the surface in terms of vocabulary, semantics, and phonological characteristics, with few attempts to delve into its internal phonetic structure. This study addresses this gap by using Praat software and theories of tongue position and formants to analyze rhyme vowels in Chongqing hip-hop lyrics. It examines formant frequencies (F1, F2, F3), pitch, and duration of vowels from local hip-hop artists' works. Results reveal that these vowels have distinct regional acoustic characteristics, differing from standard Mandarin, with lower formant frequencies aligning with the dialect's low-pitched nature. In addition, the study confirmed the phonetic changes that occurred in the 1970s, such as /ɤ/ → /ɛ/, /aʊ/, /uɔ/. This research enriches our understanding of Chongqing dialect's acoustic features and offers new insights for interdisciplinary studies in dialect phonetics and music linguistics.

Differentiating subjects through the comparison of their recorded speech is a common endeavor in speaker characterization. When using an acoustic-based approach, this task typically involves scrutinizing specific acoustic parameters and assessing their discriminatory capacity. This experimental study aimed to evaluate the speaker discriminatory power of vowel formants-resonance peaks in the vocal tract-in two different speaking styles: Dialogue and Interview. Different testing procedures were applied, specifically metrics compatible with the likelihood ratio paradigm. Only high-quality recordings were analyzed in this study. The participants were 20 male Brazilian Portuguese (BP) speakers from the same dialectal area. Two speaker-discriminatory power estimates were examined through Multivariate Kernel Density analysis: Log cost-likelihood ratios (Cllr) and equal error rates (EER). As expected, the discriminatory performance was stronger for style-matched analyses than for mismatched-style analyses. In order of relevance, F3, F4, and F1 performed the best in style-matched comparisons, as suggested by lower Cllr and EER values. F2 performed the worst intra-style in both Dialogue and Interview. The discriminatory power of all individual formants (F1-F4) appeared to be affected in the mismatched condition, demonstrating that discriminatory power is sensitive to style-driven changes in speech production. The combination of higher formants 'F3 + F4' outperformed the combination of lower formants 'F1 + F2'. However, in mismatched-style analyses, the magnitude of improvement in Cllr and EER scores increased as more formants were incorporated into the model. The best discriminatory performance was achieved when most formants were combined. Applying multivariate analysis not only reduced average Cllr and EER scores but also influenced the overall probability distribution, shifting the probability density distribution towards lower Cllr and EER values. In general, front and central vowels were found more speaker discriminatory than back vowels as far as the 'F1 + F2' relation was concerned.

In his 1989 review of vowel perception [J. Acoust. Soc. Am. 85, 2088–2113], Terry Nearey observed that the acoustic properties of vowels vary substantially across talkers due to differences in talker size. Taller speakers tend to have lower formant frequencies and lower fundamental frequencies than shorter speakers, and listeners appear to take these relationships into account in vowel identification. In this talk, we follow up some of the questions raised in that paper, reviewing recent findings on the perception of age, gender, and talker height in children’s voices. Children exhibit substantial age-related changes in fundamental and formant frequencies due to growth of the larynx and vocal tract, presenting an interesting opportunity to explore the perceptual consequences of these changes. Listeners’ perceptual judgments of age and gender reveal complex interdependencies, consistent with the idea that these indexical attributes are jointly estimated, in a manner that reflects their shared dependence on acoustic parameters related to perceived talker height.

Understanding speech in a noisy environment, as opposed to speech in quiet, becomes increasingly more difficult with increasing age. Using the quiet-aged gerbil, we studied the effects of aging on speech-in-noise processing. Specifically, behavioral vowel discrimination and the encoding of these vowels by single auditory-nerve fibers were compared, to elucidate some of the underlying mechanisms of age-related speech-in-noise perception deficits. Young-adult and quiet-aged Mongolian gerbils, of either sex, were trained to discriminate a deviant naturally-spoken vowel in a sequence of vowel standards against a speech-like background noise. In addition, we recorded responses from single auditory-nerve fibers of young-adult and quiet-aged gerbils while presenting the same speech stimuli. Behavioral vowel discrimination was not significantly affected by aging. For both young-adult and quiet-aged gerbils, the behavioral discrimination between /eː/ and /iː/ was more difficult to make than /eː/ vs. /aː/ or /iː/ vs. /aː/, as evidenced by longer response times and lower d' values. In young-adults, spike timing-based vowel discrimination agreed with the behavioral vowel discrimination, while in quiet-aged gerbils it did not. Paradoxically, discrimination between vowels based on temporal responses was enhanced in aged gerbils for all vowel comparisons. Representation schemes, based on the spectrum of the inter-spike interval histogram, revealed stronger encoding of both the fundamental and the lower formant frequencies in fibers of quiet-aged gerbils, but no qualitative changes in vowel encoding. Elevated thresholds in combination with a fixed stimulus level, i.e., lower sensation levels of the stimuli for old individuals, can explain the enhanced temporal coding of the vowels in noise. These results suggest that the altered auditory-nerve discrimination metrics in old gerbils may mask age-related deterioration in the central (auditory) system to the extent that behavioral vowel discrimination matches that of the young adults.

Past studies have reported that there are higher sound-pressure levels for each vowel in a child’s ear canal than those in adults due to reduced volume and a shorter ear canal. Furthermore, longer vocal tracts are associated with lower formant frequencies, and vice versa. The structural differences in this regard may reflect the difference in the occlusion effect. Thus, the present study compares the sound pressure levels (SPLs) and first formant frequencies of children and adults with normal hearing and determines the best vowel stimulus to assess the occlusion effect. A repeated measures research design was utilized to investigate the best stimulus with which to measure the occlusion effect among children and adults. Group 1 included ten children, and Group 2 comprised ten adults with normal hearing. The SPLs at frequencies between 200 Hz and 1000 Hz for three uttered vowels, with steps of 100 Hz, were measured using a hearing aid analyzer. The recorded vowels were saved in a ‘.wav’ format for formant frequency analysis. Furthermore, a paired comparison method was used to identify the vowel stimulus that most effectively induced the occlusion effect. A significantly higher SPL was observed for children compared to adults for each vowel. The formant frequency F1 value was higher for children than adults for each vowel, constituting a significant finding. In the paired comparison, the occlusion effect was reported to be significantly greater with respect to the vowel /u/ among adults, while it was reported to be greater in relation to the vowel /i/ among children. The vowel /u/ was the best stimulus with which to assess the occlusion effect among adults. The vowel /i/ was the best stimulus with which to assess the occlusion effect among children.

ABSTRACT Voice is an important biological cue, which may reveal a significant amount of information about an individual. Particularly in males, it plays a crucial role in processes like male competition or sexual selection. Additionally, voice can provide a cue for body size assessment. This study investigates the relationship between male voice characteristics and physical features (assessed by women) and determines the accuracy of these assessments. Three groups of female judges assessed 60 male voices (20 different voices per group) across seven categories of male physical features: height, body fat, musculature, body shape, hirsuteness, age and strength. Recordings of five vowels and sentence and number of anthropometric measurements were made for each of the studied men. Intra- and extragroup agreement of assessments of men’s physical characteristics was demonstrated. Men with lower fundamental frequency (F0 ) and lower formant dispersion (Df ) values were perceived as being heavier, older, stronger and more likely to have chest hair. However, across all the analysed fields of assessment, no accuracy was registered between estimates and men’s actual physical characteristics. These findings suggest that females were guided by stereotypes in their assessment of men’s appearance from voice alone. We propose the size exaggeration hypothesis as an explanation of this phenomenon

Formant-Aware Spectral Analysis of Sustained Vowels of Pathological Breathy Voice

Distinctive acoustic changes in speech in Parkinson's disease

Abstract This study aimed to test sound-meaning relations in Japanese poetry. To this end, participants assessed the sentiments expressed in a random selection of Tanka (a specific form of Japanese poetry) on six bipolar scales comprising Evaluation (emotional valence), Potency (dominance), and Activity (arousal). The selected Tanka differed with regard to their average formant-dispersion (i.e., the distance between the first and second formant). Corroborating results of a previous study that tested the relation between formant dispersion and emotional tone in German poetry, results suggest that poems with an extremely low average formant dispersion have a significantly higher likelihood of expressing dominance and activity than poems with an extremely high formant dispersion. No significant differences regarding the Evaluation dimension were found.

Morphological disparity and evolutionary transformations in the primate hyoid apparatus

Coupling between acoustic wave propagation and mechanical vibration of wall tissue along the vocal tract has long been considered to be an important loss mechanism in speech, affecting the frequencies and bandwidths of the lower formants. However, the detailed mechanism of energy transfer between fluid and structure as the shape of the vocal tract changes over time has not been fully elucidated. To examine this question, a time-domain finite-volume simulation of quasi-one-dimensional fluid flow and mechanical wall vibration was derived from underlying conservation laws. By calculating the eigenvalues and left and right eigenfunctions of the resulting implicit matrix recursion at each point in time, the sound field can be decomposed into modal vibrations describing coupled motion of air and tissue. Standing waves in the fluid within the vocal tract create sound waves that propagate in the wall tissue. Conversely, standing waves in the wall tissue excite waves in the fluid that propagate as sound. The coupling between airborne and mechanical modes of vibration and the transfer of energy between the two systems can easily be understood by examining the time-varying amplitude and phase of the spatial eigenfunctions. Illustrations are provided for simulations of VCV transitions.

Speech production data collection has been significantly impacted by COVID-19 restrictions. Sound-treated recording spaces and high-quality recording devices are inaccessible, and face-to-face interactions are limited. We investigated alternative recording methods that produce data suitable for phonetic analysis, and are accessible to people in their homes. We examined simultaneous recordings of pure tones at seven frequencies (50 Hz, every 100 Hz between 100 Hz and 600 Hz), and three repetitions of the primary cardinal vowels elicited from five trained speakers. Recordings were made using the ZOOM meeting application and non-lossy format smartphone applications (Awesome Voice Recorder, Recorder), comparing these with Zoom H6N reference recordings. F0, F1-5, and duration based on manual segmentation were measured. F0 is highly correlated between the three devices for vowels and tones. Lower formants are also significantly correlated though not as robustly. The upper formants showed more variation as reported in the literature. Both phone and ZOOM performed better for vowels than tones. Phone segmentation generated reliable duration values differing from H6N segmentation by ∼18 ms. However, irregular waveforms and filtering algorithm artefacts caused considerable differences for ZOOM (∼119 ms). Our preliminary study suggests phone recordings are a viable option for some phonetic studies (e.g., prosody). Future analysis of natural speech data will prove insightful.

Acoustic voice spaces for English speakers are characterized mainly by variability in F0, the balance between higher harmonic amplitudes and inharmonic energy, and higher formant frequencies [JASA 146(4), 3011 (2019)]. We extended this investigation to another language to test the hypothesis that a few biologically relevant measures will emerge commonly across languages, while remaining variance will depend on the structure of the language. This hypothesis was tested against sentence productions from 5 female and 5 male speakers of Seoul Korean. Like English, Korean does not have tone or phonation contrasts, but Seoul Korean exhibits specific phrase intonation patterns. PCAs were performed on scaled values of F0, formant frequencies, spectral noise, source spectral shape, and their variability, measured from vowels and approximants. Results revealed striking similarities between the acoustic voice spaces derived from Korean speakers and those for English speakers. For Korean voices, F0 and variability in lower formant frequencies (i.e., vowel quality) accounted for the most acoustic variance within and across talkers, presumably due to Seoul speakers' systematic use of these measures for phrasal/accentual information. These measures were insignificant for English voices. Our findings suggest that acoustic voice spaces are shaped by both biologically and phonologically relevant factors. [Work supported by NIH/NSF.]

We tested the hypothesis that phonosemantic iconicity––i.e., a motivated resonance of sound and meaning––might not only be found on the level of individual words or entire texts, but also in word combinations such that the meaning of a target word is iconically expressed, or highlighted, in the phonetic properties of its immediate verbal context. To this end, we extracted single lines from German poems that all include a word designating high or low dominance, such as large or small, strong or weak, etc. Based on insights from previous studies, we expected to find more vowels with a relatively short distance between the first two formants (low formant dispersion) in the immediate context of words expressing high physical or social dominance than in the context of words expressing low dominance. Our findings support this hypothesis, suggesting that neighboring words can form iconic dyads in which the meaning of one word is sound-iconically reflected in the phonetic properties of adjacent words. The construct of a contiguity-based phono-semantic iconicity opens many venues for future research well beyond lines extracted from poems.

Dominance of lower formants of Korean vowels /o/–/u/ in perceptual identification by Seoul dialect listeners

This paper presents a study on Malay vowel formants of different age group between young adults and aged people. About 12 of the available young adult speech (6 males and 6 females; mean age 23 years) and 4 of the recorded aged people speech (2 males and 2 females; mean 67.3 years) were examined for analysis of formants to study the effect of age and gender. This work is significant in studying the hypothesis that the formant of aged people is lower than young adult population. The findings obtained shows that the formant of aged group is not critically affected by their age and male groups produces lower formant frequencies compared to the female groups either young adult or aged people. Formant frequency values also subject to variation due to the influence of surrounding phonemes.

Do men with more masculine voices have better immunocompetence?

Previous studies have claimed that lower formants should be weighted more than higher formants in a perceptual model of vowel perception (e.g., Schwartz et al., 1997). Given this formant weighting hypothesis, and if vowels have acoustic targets, vowels should be more variable in higher formant frequencies. Here, we examined within-speaker variability for five English vowels /æ, ʌ, ɔ, ɛ, ɪ/ in various contexts as produced by 32 speakers in the x-ray microbeam database (Westbury, 1994). For variabilities of the first three formants, only /ɔ/ follows this prediction (i.e., variability: F3 > F2 > F1) while /æ/ exhibits the opposite pattern; if we ignore F3 (as being less reliably measured), most vowels conform to the prediction (i.e., variability: F2 > F1), except for /æ/. Although the F2 variability is generally consistent with the perceptual model of vowel perception, it is also consistent with a possibly greater effect of consonant coarticulation (which is extensive here) on F2 relative to F1; this requires more testing. Further, while these results do not fully conform to the prediction made by the hypotheses, coproduction effects arising from the diverse contexts likely interact with the expected tendency. Correlation with observed kinematic variabilities will also be discussed. [Work supported by NIH grant DC-002717.]