The acoustics of word-initial and word-internal voiced stops in Somali

This article seeks to determine the acoustic correlates of gemination in Standard Somali (Afroasiatic, Cushitic), in particular whether closure duration is the primary acoustic correlate distinguishing singleton and geminate stops, with immediate consequences for the analysis of word-initial strengthening. We provide an acoustic analysis of word-initial and word-internal voiced singletons as well as of their geminate counterparts on the basis of a production experiment conducted with four native speakers. Three temporal and four non-temporal acoustic properties of /b d ɡ/ and /bb dd ɡɡ/ are examined and systematically compared (closure duration, release burst duration, vowel duration; and closure amplitude, release amplitude, presence of a release burst, (de)voicing). We argue that the opposition between singleton and geminate voiced stops is primarily realized as the manner contrast approximant [β̞ ð̞ ɣ̞] vs. stop [b d ɡ]. Word-initially, Somali exhibits various peculiarities that are reminiscent of the cross-linguistically attested phenomenon of domain-initial strengthening. This article provides the first study of this phenomenon in Somali. We establish that word-initial /b d ɡ/ and word-medial /bb dd ɡɡ/ share the same closure duration, release burst duration, and vowel duration within the Prosodic Word. They also have a similar closure amplitude, and voicing properties. Moreover, the acoustic properties of word-initial /b d ɡ/ remain constant, and do not depend on their position in the prosodic hierarchy. On the basis of these results, the article also aims at providing new insights in the phonological representation of Somali geminates and word boundaries, and thus contributes to the understanding of word-initial strengthening in Somali.

Evaluation of a Fatigue Detector Using Eye Closure-Associated Indicators Acquired from Truck Drivers in a Simulator Study

This paper presents a camera-based prototype sensor for detecting fatigue and drowsiness in drivers, which are common causes of road accidents. The evaluation of the detector operation involved eight professional truck drivers, who drove the truck simulator twice—i.e., when they were rested and drowsy. The Fatigue Symptoms Scales (FSS) questionnaire was used to assess subjectively perceived levels of fatigue, whereas the percentage of eye closure time (PERCLOS), eye closure duration (ECD), and frequency of eye closure (FEC) were selected as eye closure-associated fatigue indicators, determined from the images of drivers’ faces captured by the sensor. Three alternative models for subjective fatigue were used to analyse the relationship between the raw score of the FSS questionnaire, and the eye closure-associated indicators were estimated. The results revealed that, in relation to the subjective assessment of fatigue, PERCLOS is a significant predictor of the changes observed in individual subjects during the performance of tasks, while ECD reflects the individual differences in subjective fatigue occurred both between drivers and in individual drivers between the ‘rested’ and ‘drowsy’ experimental conditions well. No relationship between the FEC index and the FSS state scale was found.

Comparing the Temporal Aspects of Velopharyngeal Closure in Children with and without Cleft Palate

<b><i>Introduction:</i></b> Children with cleft palate exhibit differences in the 4 temporal components of nasalization (nasal onset and offset intervals, nasal consonant duration, and total speech duration), with various patterns having been noted based on different languages. Thus, the current study aimed to examine the temporal aspects of velopharyngeal closure in children with and without cleft palate; this is the first study to do so in the Turkish language. <b><i>Methods:</i></b> This study evaluated and compared the 4 temporal characteristics of velopharyngeal closure in children (aged 6–10 years) with (<i>n</i> = 28) and without (<i>n</i> = 28) cleft palate using nonword consonant and vowel speech samples, including the bilabial nasal-to-stop combination /mp/ and the velar nasal-to-stop combination /ηk/. Acoustic data were recorded using a nasometer, after which acoustic waveforms were examined to determine the 4 temporal components of nasalization. Flexible nasoendoscopy was then used to evaluate velopharyngeal closure patterns. <b><i>Results:</i></b> With regard to the 4 closure patterns, significant differences in the nasal offset interval (<i>F</i>_4–25 = 10.213, <i>p</i> = 0.04; <i>p</i> &#x3c; 0.05) and the nasal consonant duration ratio (<i>F</i>_4–25 = 12.987, <i>p</i> = 0.02; <i>p</i> &#x3c; 0.05) were observed for only /ampa/. The coronal closure pattern showed the longest closure duration (0.74 s). Children with cleft palate showed prolonged temporal parameters in all 4 characteristics, reflecting oral-nasal resonance imbalances. In particular, the low vowel sound /a/ was significantly more prolonged than the high vowel sounds /i/ and /u/. <b><i>Conclusions:</i></b> The examined temporal parameters offer more accurate characterizations of velopharygeal closure, thereby allowing more accurate clinical assessments and more appropriate treatment procedures. Children with cleft palate showed longer nasalization durations compared to those without the same. Thus, the degree of hypernasality in children with cleft palate may affect the temporal aspects of nasalization.

Why phonetically-motivated constraints do not lead to phonetic determinism: The relevance of aspiration in cueing NC sequences in Tumbuka

This paper examines the role of phonetic cues to postnasal laryngeal contrasts, language-specific differences in the use of these cues, and the phonetic naturalness of the different cues. While many studies have shown that long stop closure duration is a well-established cue to voicelessness in the postnasal context (see, e.g., Cohn & Riehl 2012, who claim this to be a universal property), the present study focusses on the role of aspiration noise in maintaining a voicing contrast in the postnasal environment. It provides experimental data from the Bantu language Tumbuka to illustrate that aspiration noise can preserve a postnasal laryngeal contrast even when stop closure duration is short. Though typologically less common, we show that the use of aspiration as a cue is also phonetically motivated. Furthermore, we show that such phonetic motivation should not be directly incorporated into phonology (e.g., as markedness constraints in OT). Instead, we employ the BiPhon model (Boersma 2007), which allows for a strict distinction between the modules of phonetics and phonology, and which formalizes the mapping of phonetic cues onto phonological representations via cue constraints, avoiding the problem of phonetic determinism.

On the interaction of phonetic parameters implementing the voiced / voiceless phonological opposition in Standard Modern Russian

The paper reports new data obtained in the experimental study of voice coarticulation of voiced and voiceless obstruents adjacent to sonorant depending on the place and manner of articulation of these consonants in Standard Modern Russian. The experimental results revealed the voice coarticulation of the obstruent in word-internal clusters of [sonorant + obstruent + sonorant] coronal consonants, possibly due to the preceding homorganic nasal consonant. In the case of sonorants [nasal + voiceless stop + vibrant] that are not identical in place and manner of articulation, the closure part of the dental stop becomes voiced throughout, with this phonation type accommodation not leading, nevertheless, to the voiced / voiceless phoneme neutralization since the contrast in question is still maintained by phonetic parameters other than voice (phonation itself). These are closure duration, burst duration, and relative overall intensity. On the contrary, in the case of dental sonorants [nasal + voiceless stop + nasal] being identical in place and manner of articulation, the contrast in burst duration is eliminated since no burst of dental stop is found in the position before homorganic nasal, with the closure part of the stop not acquiring voicing to prevent the voiced / voiceless phoneme neutralization. In conclusion, it is argued that in Standard Modern Russian, the phonetic parameter [relative overall intensity] is less significant in the hierarchical structure of distinctive phonological feature than [closure voicing] and [burst duration] ones since it cannot serve as the only parameter distinguishing the voiced and voiceless obstruents in the intersonorant position.

Automatic Estimation of Laryngeal Vestibule Closure Duration Using High-Resolution Cervical Auscultation Signals

Purpose Safe swallowing requires adequate protection of the airway to prevent swallowed materials from entering the trachea or lungs (i.e., aspiration). Laryngeal vestibule closure (LVC) is the first line of defense against swallowed materials entering the airway. Absent LVC or mistimed/shortened closure duration can lead to aspiration, adverse medical consequences, and even death. LVC mechanisms can be judged commonly through the videofluoroscopic swallowing study; however, this type of instrumentation exposes patients to radiation and is not available or acceptable to all patients. There is growing interest in noninvasive methods to assess/monitor swallow physiology. In this study, we hypothesized that our noninvasive sensor-based system, which has been shown to accurately track hyoid displacement and upper esophageal sphincter opening duration during swallowing, could predict laryngeal vestibule status, including the onset of LVC and the onset of laryngeal vestibule reopening, in real time and estimate the closure duration with a comparable degree of accuracy as trained human raters. Method The sensor-based system used in this study is high-resolution cervical auscultation (HRCA). Advanced machine learning techniques enable HRCA signal analysis through feature extraction and complex algorithms. A deep learning model was developed with a data set of 588 swallows from 120 patients with suspected dysphagia and further tested on 45 swallows from 16 healthy participants. Results The new technique achieved an overall mean accuracy of 74.90% and 75.48% for the two data sets, respectively, in distinguishing LVC status. Closure duration ratios between automated and gold-standard human judgment of LVC duration were 1.13 for the patient data set and 0.93 for the healthy participant data set. Conclusions This study found that HRCA signal analysis using advanced machine learning techniques can effectively predict laryngeal vestibule status (closure or opening) and further estimate LVC duration. HRCA is potentially a noninvasive tool to estimate LVC duration for diagnostic and biofeedback purposes without X-ray imaging.

Context effects on the acoustic realization of stops and affricates in Northern Pwo Karen

Studies have shown that the voice onset time (VOT) of alveolo-palatal affricates is the longest, followed by velars, dental/alveolars, and bilabials. In a reciprocal pattern, closure duration is the longest for bilabials, followed by dental/alveolars, and then velars. Longer VOT is also associated with high and front vowels and tones with rising components. Moreover, the VOT of voiceless unaspirated stops is reported to be longer and closure duration shorter in nasal words. Finally, the voiceless interval has been described as constant in some languages and inconstant in others. Given the evidence of previous research, this study investigates the effects of place, nasality, tone, and vowel quality on the VOT, closure duration, and voiceless interval of the voiced and voiceless obstruents of Northern Pwo Karen (N. Pwo), a language of Thailand. N. Pwo (ISO 639-3 pww) is a ‘true voicing’ language with a three-way distinction in stops, voiceless aspirated and unaspirated affricates, oral and nasal vowels, and six tones (four modal tones and two glottalized tones). In N. Pwo, the place effects on VOT and closure duration pattern reciprocally. Whereas, both VOT and the voiceless interval are longer before oral vowels compared to nasal vowels. VOT is longest before the mid tone, which has a slight rise, while it is the shortest before the falling-glottalized tone. This pattern is reversed for the closure duration of aspirates and voiced stops. Finally, VOT, closure duration, and the voiceless interval are the longest before high and front vowels.