Stop Consonants Research Articles

Mapping the spectrotemporal regions influencing perception of French stop consonants in noise

Understanding how speech sounds are decoded into linguistic units has been a central research challenge over the last century. This study follows a reverse-correlation approach to reveal the acoustic cues listeners use to categorize French stop consonants in noise. Compared to previous methods, this approach ensures an unprecedented level of detail with only minimal theoretical assumptions. Thirty-two participants performed a speech-in-noise discrimination task based on natural /aCa/ utterances, with C = /b/, /d/, /g/, /p/, /t/, or /k/. The trial-by-trial analysis of their confusions enabled us to map the spectrotemporal information they relied on for their decisions. In place-of-articulation contrasts, the results confirmed the critical role of formant consonant-vowel transitions, used by all participants, and, to a lesser extent, vowel-consonant transitions and high-frequency release bursts. Similarly, for voicing contrasts, we validated the prominent role of the voicing bar cue, with some participants also using formant transitions and burst cues. This approach revealed that most listeners use a combination of several cues for each task, with significant variability within the participant group. These insights shed new light on decades-old debates regarding the relative importance of cues for phoneme perception and suggest that research on acoustic cues should not overlook individual variability in speech perception.

Lenition in L2 Spanish: The Impact of Study Abroad on Phonological Acquisition.

Objective: This study investigated the degrees of lenition, or consonantal weakening, in the production of Spanish stop consonants by native English speakers during a study abroad (SA) program. Lenition is a key phonological process in Spanish, where voiced stops (/b/, /d/, /ɡ/) typically weaken to fricatives or approximants in specific phonetic environments. For L2 learners, mastering this subtle process is essential for achieving native-like pronunciation. Methods: To assess the learners' progress in acquiring lenition, we employed Phonet, a deep learning model. Unlike traditional quantitative acoustic methods that focus on measuring the physical properties of speech sounds, Phonet utilizes recurrent neural networks to predict the posterior probabilities of phonological features, particularly sonorant and continuant characteristics, which are central to the lenition process. Results: The results indicated that while learners showed progress in producing the fricative-like variants of lenition during the SA program and understood how to produce lenition in appropriate contexts, the retention of these phonological gains was not sustained after their return. Additionally, unlike native speakers, the learners never fully achieved the approximant-like realization of lenition. Conclusions: These findings underscore the need for sustained exposure and practice beyond the SA experience to ensure the long-term retention of L2 phonological patterns. While SA programs offer valuable opportunities for enhancing L2 pronunciation, they should be supplemented with ongoing support to consolidate and extend the gains achieved during the immersive experience.

A Preliminary Investigation of Within-Word Silent Intervals Produced by Children With and Without Neurodevelopmental Disorders.

The categorization of silent intervals during speech production is necessary for accurate measurement of articulation rate and pauses. The primary purpose of this preliminary study was to examine the within-word silent interval associated with the stop closure in word-final stop consonants produced by children with and without neurodevelopmental disorders. Seven children diagnosed with either cerebral palsy or Down syndrome (i.e., children with neurodevelopmental disorders) and eight typically developing children produced a reading passage. Participants were between the ages of 11 and 16 years. Fifty-eight words from the reading passage were identified as having word-final stop consonants. The closure duration of the word-final stop consonant was calculated, both in absolute duration and percent pause time. The articulation rate of the entire passage was calculated. The number of closure durations that met or exceeded the minimum duration threshold to be considered a pause (150 ms) was examined descriptively. Children with neurodevelopmental disorders produced significantly longer closure durations and significantly slower articulation rates than typically developing children. Children with neurodevelopmental disorders produced closure durations that met or exceeded the minimum duration threshold of a pause, but typically developing children, generally, did not. These data indicate the need to examine the location of silent intervals that meet the minimum duration threshold of a pause and correct for articulatory events during the measurement of articulation rate and pauses in children with neurodevelopmental disorders.

Enhancing analysis of diadochokinetic speech using deep neural networks

Diadochokinetic speech tasks (DDK) involve the repetitive production of consonant-vowel syllables. These tasks are useful in detecting impairments, differential diagnosis, and monitoring progress in speech-motor impairments. However, manual analysis of those tasks is time-consuming, subjective, and provides only a rough picture of speech. This paper presents several deep neural network models working on the raw waveform for the automatic segmentation of stop consonants and vowels from unannotated and untranscribed speech. A deep encoder serves as a features extractor module, replacing conventional signal processing features. In this context, diverse deep learning architectures, such as convolutional neural networks (CNNs) and large self-supervised models like HuBERT, are applied for the extraction process. A decoder model uses derived embeddings to identify frame types. Consequently, the paper studies diverse deep architectures, ranging from linear layers, LSTM, CNN, and transformers. These architectures are assessed for their ability to detect speech rate, sound duration, and boundary locations on a dataset of healthy individuals and an unseen dataset of older individuals with Parkinson’s Disease. The results reveal that an LSTM model performs better than all other models on both datasets and is comparable to trained human annotators.

An Investigation of Language-Specific and Orthographic Effects in L2 Arabic geminate production by Advanced Japanese- and English-speaking learners.

Research has indicated that second-language learners have difficulty producing geminates accurately. Previous studies have also shown an effect of orthography on second-language speech production. We tested whether the existence of a contrast in the first language phonology for length aids the second-language production of the same contrast. Furthermore, we examined the effect of exposure to orthographic input on geminate consonant production in a cross-script context. We tested the production of Arabic geminate-singleton stop consonants [/bː/-/b/, /tː/-/t/, /dː/-/d/, and /kː/-/k/], a nasal stop consonant /mː/-/m/, and an emphatic stop consonant /tˤː/-/tˤ/, as well as the effect of the diacritic used in Arabic to mark gemination in a delayed imitation task and two reading tasks (ortho-with diacritics and ortho-without diacritics). A comparison of the productions of advanced Japanese-speaking learners, English-speaking learners, and an Arabic control group showed that both learner groups were able to produce Arabic geminate stops; however, the Japanese-speaking learners exhibited an advantage over the English-speaking learners in the auditory-only task and in the presence of diacritics, highlighting the fact that orthographic effects may occur in some cross-script contexts.

Optimization-based planning of speech articulation using general Tau Theory

This paper presents a model of speech articulation planning and generation based on General Tau Theory and Optimal Control Theory. Because General Tau Theory assumes that articulatory targets are always reached, the model accounts for speech variation via context-dependent articulatory targets. Targets are chosen via the optimization of a composite objective function. This function models three different task requirements: maximal intelligibility, minimal articulatory effort and minimal utterance duration. The paper shows that systematic phonetic variability can be reproduced by adjusting the weights assigned to each task requirement. Weights can be adjusted globally to simulate different speech styles, and can be adjusted locally to simulate different levels of prosodic prominence. The solution of the optimization procedure contains Tau equation parameter values for each articulatory movement, namely position of the articulator at the movement offset, movement duration, and a parameter which relates to the shape of the movement’s velocity profile. The paper presents simulations which illustrate the ability of the model to predict or reproduce several well-known characteristics of speech. These phenomena include close-to-symmetric velocity profiles for articulatory movement, variation related to speech rate, centralization of unstressed vowels, lengthening of stressed vowels, lenition of unstressed lingual stop consonants, and coarticulation of stop consonants.

Comparison the Voice Onset Time (VOT) of Postlingual Cochlear Implant Users and Normal Peers in the CAPE_V Sentences as Continues Speech Task

BackgroundAuditory perception plays a crucial role in speech and language development, emphasizing concerns about hearing loss. While cochlear implantation nearly tackles challenges associated with post-lingual hearing loss in adults, the importance of "auditory feedback" and acoustic assessment becomes crucial for evaluating speech disorders and devising effective treatments. This study aims to address the gap in assessing Voice Onset Time (VOT) as an indicator of nuanced variations in the speech of cochlear implant users during a continuous speech task. MethodRecordings of Persian CAPE-V sentences were obtained from 25 cochlear implant (CI) users and 25 healthy speakers, with a mean age of 33.2 years (SD=11.5, range=18-55 years). Ten words, incorporating both voiced and voiceless consonants, were selected from the CAPE-V sentences. VOT measurements for the specified stop consonants at the initial syllables of these chosen words were computed using PRAAT. A comparative analysis between the two age- and gender-matched groups was conducted using an independent sample t-test. Subsequently, ANCOVA was employed to examine the influence of demographic factors on VOT values among CI participants. ResultsUnvoiced consonant /p/ in /po/, /pɑ/, /pe/, and /pa/ syllables had higher VOT values in the healthy group, while the voiced consonant /d/ in /da/ and /di/ syllables demonstrated higher VOT values in the CI group. (P<0.05) Apart from /po/ and /di/ syllables, no significant impacts of demographic factors on VOT values were observed (P≥0.8). ConclusionDespite the improvement in speech quality after cochlear implantation, subtle differences persist. The motor theory, which underscores the impact of auditory inputs on temporal coordination, highlights the role of VOT in speech discrimination. Various linguistic factors affect VOT, including articulation position, vowel context, and raised vowels. While CI enhances syllable distinction, challenges in articulation for adults suggest a need for targeted training in rehabilitation programs, ultimately enhancing the quality of life for CI users.

Positional error distribution in Thai speakers’ acquisition of Korean stop consonants: A speech corpus analysis

Positional error distribution in Thai speakers’ acquisition of Korean stop consonants: A speech corpus analysis

The effect of native language and bilingualism on multimodal perception in speech: A study of audio-aerotactile integrationa).

Previous studies of speech perception revealed that tactile sensation can be integrated into the perception of stop consonants. It remains uncertain whether such multisensory integration can be shaped by linguistic experience, such as the listener's native language(s). This study investigates audio-aerotactile integration in phoneme perception for English and French monolinguals as well as English-French bilingual listeners. Six step voice onset time continua of alveolar (/da/-/ta/) and labial (/ba/-/pa/) stops constructed from both English and French end points were presented to listeners who performed a forced-choice identification task. Air puffs were synchronized to syllable onset and randomly applied to the back of the hand. Results show that stimuli with an air puff elicited more "voiceless" responses for the /da/-/ta/ continuum by both English and French listeners. This suggests that audio-aerotactile integration can occur even though the French listeners did not have an aspiration/non-aspiration contrast in their native language. Furthermore, bilingual speakers showed larger air puff effects compared to monolinguals in both languages, perhaps due to bilinguals' heightened receptiveness to multimodal information in speech.

L1 Japanese Perceptual Drift in Late Learners of L2 English

This study presents evidence of second language (L2) influence on first language (L1) perception of alveolar stops. Sixty-one L1 Japanese late learners of L2 English (onset ~12 years old) in Japan (N = 31) and in the US (N = 30) participated. We examined late L2 learners’ L2 perceptual ability and L1 perception drift by administering three perception tasks (AX discrimination, forced categorization, and goodness rating) on word-initial stop consonants. The L2 learners’ L1 Japanese and L2 English data were compared to those of Japanese and English monolinguals, respectively (N = 21, N = 16). All participants’ production data were also gathered to examine potential perception-production relationships. Late learners’ sensitivity patterns along a synthesized /da–ta/ continuum differed significantly from those of monolingual speakers, with a sensitivity peak location between the monolingual Japanese and English groups. This suggests that late learners’ voicing category boundaries may have been influenced by L2 English learning. The L2 learners’ goodness rating patterns of L1 Japanese stimuli also showed evidence of L1 perceptual drift: L2 learners tended to be more accepting of Japanese stimuli with longer VOTs compared to Japanese monolinguals.

Production and perception of stop voicing in Central Australian Aboriginal English: A cross-generational study

ABSTRACT This paper reports on a series of studies investigating the production and perception of stop voicing contrasts in speakers of Central Australian Aboriginal English (CAAE; Alice Springs, Australia). Study 1 investigated Voice Onset Time (VOT) and Constriction Duration (CD) in stop consonants in naturalistic adult speech, and the speakers produced a VOT-based voicing distinction in word-initial stops, while medial voiceless stops differ from voiced stops in having both longer VOTs and longer CDs, at least for the syllable onset position. Study 2 investigated the implementation of stop voicing contrasts (VOT and CD) in a cohort of child CAAE speakers, and the results are consistent with the adult CAAE data, suggesting predictable intergenerational transmission. Finally, Study 3 tested child speakers’ perception of stop voicing contrasts using a mispronunciation detection task, where the participants demonstrated above-chance performance for the voicing distinction across all places of articulation. Together, the findings suggest that CAAE has phonemic stop voicing distinctions, like Mainstream Australian English, and that CAAE medial stops are jointly cued by both VOT and CD, a feature shared with the contact language, Kriol.

Categorical Perception of Lexical Tones and Stops in Mandarin-Speaking Musicians and Nonmusicians

This study investigates the perception of Mandarin lexical tones and stops to examine the degree of overlap between music and language. Eighteen musicians and 21 nonmusicians participated in a typical categorical perception task. Results showed that musicians and nonmusicians had comparable degree of categorical perception of tones and stops. Compared to nonmusicians, musicians exhibited enhanced sensitivities to within-category lexical tone stimuli. However, this improved ability was not observed in the perception of stops. These findings imply that musical experience strengthens the acuity of subtle low-level acoustic variations between within-category lexical tone stimuli without interfering with the high-level phonological representations of lexical tones, and this facilitatory effect is selective and could not readily extend to stop consonants in native language.

Fusion of dichotic consonants in normal-hearing and hearing-impaired listenersa).

Hearing-impaired (HI) listeners have been shown to exhibit increased fusion of dichotic vowels, even with different fundamental frequency (F0), leading to binaural spectral averaging and interference. To determine if similar fusion and averaging occurs for consonants, four natural and synthesized stop consonants (/pa/, /ba/, /ka/, /ga/) at three F0s of 74, 106, and 185 Hz were presented dichotically-with ΔF0 varied-to normal-hearing (NH) and HI listeners. Listeners identified the one or two consonants perceived, and response options included /ta/ and /da/ as fused percepts. As ΔF0 increased, both groups showed decreases in fusion and increases in percent correct identification of both consonants, with HI listeners displaying similar fusion but poorer identification. Both groups exhibited spectral averaging (psychoacoustic fusion) of place of articulation but phonetic feature fusion for differences in voicing. With synthetic consonants, NH subjects showed increased fusion and decreased identification. Most HI listeners were unable to discriminate the synthetic consonants. The findings suggest smaller differences between groups in consonant fusion than vowel fusion, possibly due to the presence of more cues for segregation in natural speech or reduced reliance on spectral cues for consonant perception. The inability of HI listeners to discriminate synthetic consonants suggests a reliance on cues other than formant transitions for consonant discrimination.

베트남인의 한국어 폐쇄음 산출에 대한 한국인의 지각 연구

The purpose of this paper is to investigate the perception patterns of Koreans regarding the production of Korean stop consonants by Vietnamese Korean language learners. For this purpose, an experiment was conducted on Koreans' perception of Vietnamese learners’ production of Korean stop consonants.&#x0D; The results of the experiment show that when the presentation sound is located at the beginning of the word, the correct answer rate was ‘/ㅌ/ 89%) &gt; /ㅋ/(88%) &gt; /ㅍ/=/ㅂ/(84%) &gt; /ㄱ/=/ㄸ/(74%) ) &gt; /ㄷ/(72%) &gt; /ㅃ/(65%) &gt; /ㄲ/(61%)', and in the case of word-medial onset consonants, ’/ㅍ/, /ㅋ/(91%) &gt; /ㅌ /(88%) &gt; /ㄷ/(68%) &gt; /ㅂ/(61%) &gt; /ㄸ/(60%) &gt; /ㄲ/(51%) &gt; /ㅃ/(46%) &gt; /ㄱ/(40%)’. Except for the case of /ㄸ/ in word-initial and /ㄱ/ in word-medial, accuracy was found to be high in the order of aspirated consonants &gt; plain consonants &gt; tense consonants for both word-initial and word-medial positions. The percentage of correct responses in the word-initial environment was higher than that in the word-medial environment, and this was revealed more clearly through matrix analysis. In both word-initial and word-medial environments, when the target sound was ‘plain’, it was confused with ‘tense’, when it was ‘tense’ it was confused with ‘aspirated’, and when it was ‘aspirated’ it was confused with ‘plain’. Looking at the correct rate for each following vowel, except for the word-medial plain consonant (/ㅣ/ &gt; /ㅜ/ &gt; /ㅏ/), in all other cases, the correct rate was high in the order of /ㅣ/ &gt; /ㅏ/ &gt; /ㅜ/. This result shows that the correct response rate for the following vowels decreases as the vowels move from the front vowels to the back vowels.

The Contribution of Aspirated Feature Information of Initial in Mandarin-Chinese Monosyllable Word Processing

The passage mainly focuses on aspirated feature of stop consonants priming effect in Mandarin-Chinese monosyllable real spoken words. The experiment contrasted 4 prime conditions of prime-target pairs: homogeneous (pa1-pa1), aspirated feature (pha1-pa1), post-homogeneous (ma1-pa1) and unrelated (lu1-pa1). In the experiment, all tonal information is matched and the aspirated feature of initial in Mandarin-Chinese monosyllable real spoken words is the variant. The latter two pairs are control groups. The data were from ten Mandarin native listeners, then they were calculated and got the mean reaction time (RT), the standard deviation (std) and standard error (std. err). By comparing with the unrelated group, the other three shows that if some segmental information are matched, there will be significant negative priming effect. The first two pairs test whether aspirated feature activate priming effect at word recognition in Mandarin-Chinese monosyllable real spoken words by auditory priming, by comparing the homogeneous (H) group with the aspirated group and post-homogeneous group, the result shows that changing the aspirated feature do have a positive priming effect.

Child-Directed Speech in Noise: Testing Signal- and Code-Based Phonetic Enhancement.

Talkers adapt their speech according to the demands of their listeners and the communicative context, enhancing the properties of the signal (pitch, intensity) and/or properties of the code (enhancement of phonemic contrasts). This study asked how mothers adapt their child-directed speech (CDS) in ways that might serve the immediate goals of increasing intelligibility, as well as long-term goals of supporting speech and language development in their children. Mothers (N = 28) participated in a real-time interactive speech production/perception paradigm, in which mothers instructed their young (3- to 5-year-old) children, or an adult listener, to select the picture corresponding to a target word. The task was performed at low and high levels (56 vs. 75 dB SPL) of background noise to examine the Lombard effects of decreased audibility on speech production. Acoustic-phonetic analyses of CDS and adult-directed speech (ADS) productions of target words and carrier phrase (e.g., "Find pig") revealed that mothers significantly enhanced the mean pitch, pitch variability, and intensity of target words in CDS, particularly at higher background noise levels and for younger children. Mothers produce CDS with a higher signal-to-noise ratio than ADS. However, limited evidence was found for phonetic enhancement of the segmental properties of speech. Although increased category separation was found in the voice onset time of stop consonants, decreased vowel category separation (an anti-enhancement effect) was observed in CDS. Mothers readily enhance the suprasegmental signal properties of their speech in CDS, but not the acoustic-phonetic properties of phonemes. This study fails to provide evidence of phonetic enhancement in preschool children in a dyadic communication task under noisy listening conditions. https://doi.org/10.23641/asha.24645423.

The Effect of Speaking Rate on the Voice Onset Time (VOT) of Bahdini Kurdish Stops

This research examines the effect of speaking rate on the voice onset time (VOT) of stop consonants in Bahdini Kurdish. 30 native speakers are chosen to take part in this study. VOT values are measured for all 10 Kurdish stop consonants produced by participants in carrier words in initial prevocalic onset position. The duration of the carrier word is also measured by using the Web MAUS service (Munich Automatic Segmentation), which is used for word duration measurements. Word duration measurements are compared to the VOT measurements to check whether they are both correlated or not based on laryngeal state and place of stop articulation (POA). Results reveal that there is an effect of speaking rate on VOT based on the three-way laryngeal contrast between the categories of voiced, voiceless aspirated and voiceless unaspirated stops in Bahdini Kurdish. VOT increases as word durations increase, which is inversely related to speaking rate. This means that VOT increases as speaking rate decreases. There is a systematic correlation between VOT and word duration based on different laryngeal states of voiced, voiceless aspirated and voiceless unaspirated stop categories. However, Place of Articulation (POA) does not show such an effect.

SÜREKLİLEŞME KAVRAMI VE KUZEYDOĞU GRUBU TÜRK LEHÇELERİNDE SÜREKLİLEŞME

The aforementioned study is based on determining the status of the concept of continuity in terms of Turkish dialects and examining its appearance in front, inner and final phonemes in Altai, Khakas and Tuva Turkish, which are the Northeast group Turkish dialects. The data of the study were collected with the document analysis technique, one of the qualitative research methods, and the words with discontinuous consonants (stop consonants) from the Old Turkish period were determined and their situation in the Northeastern group of Turkish dialects was examined. In the study, comparative and diachronic grammar method was applied and a small sample of the changes in the front, inner and final sounds of the examined sounds was given in the study. The results obtained in the study are given in the "Conclusion" section, and the sources used are in the "References" section.

Phonological redeployment for [retracted tongue root] in third language perception of Kaqchikel stops

Phonological redeployment is the theoretical ability of language learners to utilize non-local phonological knowledge from known languages in the mapping and acquisition of novel contrasts in their target languages. The current paper probes the limits of phonological redeployment in a third language acquisition scenario. The phonological features [Advanced Tongue Root] and [Retracted Tongue Root] capture a range of phonological contrasts and harmony processes in both vowels and consonants of spoken languages across the world, including, but not limited to, vowel tensing and post-velar places of articulation (e.g. uvular). Kaqchikel (cak) exhibits both a tense-lax vocalic contrast in its vowels plus a velar-uvular Place contrast in its eight stop consonant phonemes. English (eng) exhibits a tense-lax vocalic distinction but no velar-uvular distinction among its six stop phonemes. Spanish (spa) exhibits neither of these contrasts in its vowels or among its six stop phonemes. How do multilingual learners of Kaqchikel already familiar with English and Spanish, but who differ in which is their first language (L1), compare in their categorical perception of Kaqchikel stop consonants? Despite English and Spanish having a three-way Place distinction among stops in common, in a phonemic categorization task, L1 English learners of Kaqchikel were better at correctly categorizing audio recordings of Kaqchikel uvular stops than L1 Spanish learners of Kaqchikel. To account for this surprising result, I propose that the L1 English group have easier access than the L1 Spanish group to the feature underlying English's tense-lax distinction. This access allows them to redeploy that phonological feature to accurately map out the novel four-way contrast of Kaqchikel's stop consonants, and the [±RTR] specified velar-uvular distinction in particular. Therefore, phonological redeployment must be considered in models of third language acquisition.

An Acoustic Study of the Stop Consonants in Lettered-Words Produced by Chinese Mandarin Speakers

This paper presents key findings from an acoustic study on Chinese Mandarin Speakers’ realization of the stop consonants in lettered-words and the stop consonants in Chinese phrases. The research was conducted through voice recording and analysis of data collected from Chinese Mandarin speakers. Recordings of 2000 overall tokens were collected and analyzed using Praat phonetic software. The mean VOT values obtained from both lettered-words and Chinese phrases were compared and statistically tested using the Independent Samples t-test. The research findings show that first, the stop consonants in lettered-words produced by Chinese Mandarin speakers are all voiceless stop consonants, distinguished as being [+aspirated] and [-aspirated]. Second, the VOT values of [p] [t] [k] in lettered-words are significantly lower than their counterparts in Chinese phrases. Third, the stop consonants in lettered-words have the same stop pattern as those in Chinese phrases. The research presents proof that where there is phonemic similarity (but phonetic dissimilarity) across Chinese Mandarin and English, L1 phonetic properties are strong for Chinese Mandarin speakers to produce lettered-words in L1 environment, which further confirms former scholars’ conviction of mother tongue interference in L2 learning. Similar phonemes in L1 and L2 are realized identically to L1 sounds, and there is significant interference from the speaker’s native language on phonetic properties produced in L2. In addition, the research presents implication for future research that might explore other acoustic features of lettered-words in Chinese Mandarin.