Fundamental Frequency and Phonation Differences in the Production of Stop Laryngeal Contrasts of Endangered Shina

Shina is an endangered Indo-Aryan (Dardic) language spoken in Gilgit, Northern Pakistan. The present study investigates the acoustic correlates of Shina’s three-way stop laryngeal contrast across five places of articulation. A wide range of acoustic correlates were measured including fundamental frequency (F0), spectral tilt (H1*-H2*, H1*-A1*, H1*-A2*, and H1*-A3*), and cepstral peak prominence (CPP). Voiceless aspirated stops were characterized by higher fundamental frequency, spectral tilt, and cepstral peak prominence, compared to voiceless unaspirated and voiced unaspirated stops. These results suggest that Shina is among those languages which have a raising effect of aspiration on the pitch and spectral tilt onsets of the following vowels. Positive correlations among fundamental frequency, spectral tilt, and cepstral peak prominence were observed. The findings of this study will contribute to the phonetic documentation of endangered Dardic languages.

Voice Quality of Children With Cerebral Palsy

Purpose Many children with cerebral palsy (CP) are described as having altered vocal quality. The current study utilizes psychoacoustic measures, namely, low-amplitude (H1*–H2*) and high-amplitude (H1*–A2*) spectral tilt and cepstral peak prominence (CPP), to identify the vocal fold articulation characteristics in this population. Method Eight children with CP and eight typically developing (TD) peers produced vowel singletons [i, ɑ, u] and a story retell task with the same vowels in the words “beets, Bobby, boots.” H1*–H2*, H1*–A2*, and CPP were extracted from each vowel. Results were analyzed with mixed linear models to identify the effect of Group (CP, TD), Task (vowel singleton, story retell), and Vowel [i, ɑ, u] on the dependent variables. Results Children with CP have lower spectral tilt values (H1*–H2* and H1*–A2*) and lower CPP values than their TD peers. For both groups, vowel singletons were associated with lower CPP values as compared to story retell. Finally, the vowel [ɑ] was associated with higher spectral tilt and higher CPP values as compared to [i, u]. Conclusions Children with CP have more constricted and creaky vocal quality due to lower spectral tilt and greater noise. Unlike adults, children demonstrate poorer vocal fold articulation when producing vowel singletons as compared to story retell. Finally, low vowels like [ɑ] seem to be produced with less constriction and noise as compared to high vowels.

Sound change in spontaneous bilingual speech: A corpus study on the Cantonese n-l merger in Cantonese-English bilinguals

In Cantonese and several other Chinese languages, /n/ is merging with /l/. The Cantonese merger appears categorical, with /n/ becoming /l/ word-initially. This project aims to describe the status of /n/ and /l/ in bilingual Cantonese and English speech to better understand individual differences at the interface of crosslinguistic influence and sound change. We examine bilingual speech using the SpiCE corpus, composed of speech from 34 early Cantonese-English bilinguals. Acoustic measures were collected on pre-vocalic nasal and lateral onsets in both languages. If bilinguals maintain separate representations for corresponding segments across languages, smaller differences between /n/ and /l/ are predicted in Cantonese compared to English. Measures of mid-frequency spectral tilt suggest that the /n/ and /l/ contrast is robustly maintained in English, but not Cantonese. The spacing of F2-F1 suggests small differences between Cantonese /n/ and /l/, and robust differences in English. While cross-language categories appear independent, substantial individual differences exist in the data. These data contribute to the understanding of the /n/ and /l/ merger in Cantonese and other Chinese languages, in addition to providing empirical and theoretical insights into crosslinguistic influence in early bilinguals.

Effects of Age and Cochlear Implantation on Spectrally Cued Speech Categorization

Purpose Weighting of acoustic cues for perceiving place-of-articulation speech contrasts was measured to determine the separate and interactive effects of age and use of cochlear implants (CIs). It has been found that adults with normal hearing (NH) show reliance on fine-grained spectral information (e.g., formants), whereas adults with CIs show reliance on broad spectral shape (e.g., spectral tilt). In question was whether children with NH and CIs would demonstrate the same patterns as adults, or show differences based on ongoing maturation of hearing and phonetic skills. Method Children and adults with NH and with CIs categorized a /b/–/d/ speech contrast based on two orthogonal spectral cues. Among CI users, phonetic cue weights were compared to vowel identification scores and Spectral-Temporally Modulated Ripple Test thresholds. Results NH children and adults both relied relatively more on the fine-grained formant cue and less on the broad spectral tilt cue compared to participants with CIs. However, early-implanted children with CIs better utilized the formant cue compared to adult CI users. Formant cue weights correlated with CI participants' vowel recognition and in children, also related to Spectral-Temporally Modulated Ripple Test thresholds. Adults and child CI users with very poor phonetic perception showed additive use of the two cues, whereas those with better and/or more mature cue usage showed a prioritized trading relationship, akin to NH listeners. Conclusions Age group and hearing modality can influence phonetic cue-weighting patterns. Results suggest that simple nonlexical categorization tests correlate with more general speech recognition skills of children and adults with CIs.