Consonant Place Of Articulation Research Articles

Impact of Dysphonic Schoolteachers' Voices on Children's Reaction Times according to Phonemic Contrasts.

This paper aimed at observing the impact of dysphonic voice on children's reception of a linguistic message by evaluating their reaction times (RTs) to instructions given by functional dysphonic and control female schoolteachers (STs). French minimal pairs such as /muʃ/ ("mouche" fly) versus /buʃ/ ("bouche" mouth) embedded in a carrier sentence "click on the drawing of…" were produced by two groups of 10 dysphonic and control female ST, matched in age and year of experience. The phonemical contrasts observed are voicing, nasality, consonantal place of articulation, vowel roundedness, and vowel place of articulation. The experimentation was presented in the form of a computer game to children from 7 to 10 years old. Two images illustrating the target words were presented, accompanied by the oral instructions recorded by ST. With a two-button box created for the experiment, children had to click as quickly as possible on the image corresponding to the instruction. Our results show that the RTs of all children are affected by the ST's dysphonia, regardless of their age and that they have significantly longer RT when discriminating minimal pairs contrasting in voicing when the instruction is given by a dysphonic speaker compared to the same instruction given by a control speaker. These observations could be explained by the fact that functional dysphonia is associated with improper use of the vocal folds and thus an alteration of voicing.

Discriminative segmental cues to vowel height and consonantal place and voicing in whispered speech

PurposeThe acoustic signal attributes of whispered speech potentially carry sufficiently distinct information to define vowel spaces and to disambiguate consonant place and voicing, but what these attributes are and the underlying production mechanisms are not fully known. The purpose of this study was to define segmental cues to place and voicing of vowels and sibilant fricatives and to develop an articulatory interpretation of acoustic data. MethodSeventeen speakers produced sustained sibilants and oral vowels, disyllabic words, sentences and read a phonetically balanced text. All the tasks were repeated in voiced and whispered speech, and the sound source and filter analysed using the following parameters: Fundamental frequency, spectral peak frequencies and levels, spectral slopes, sound pressure level and durations. Logistic linear mixed-effects models were developed to understand what acoustic signal attributes carry sufficiently distinct information to disambiguate /i, a/ and /s, ʃ/. ResultsVowels were produced with significantly different spectral slope, sound pressure level, first and second formant frequencies in voiced and whispered speech. The low frequencies spectral slope of voiced sibilants was significantly different between whispered and voiced speech. The odds of choosing /a/ instead of /i/ were estimated to be lower for whispered speech when compared to voiced speech. Fricatives’ broad peak frequency was statistically significant when discriminating between /s/ and /ʃ/. ConclusionsFirst formant frequency and relative duration of vowels are consistently used as height cues, and spectral slope and broad peak frequency are attributes associated with consonantal place of articulation. The relative duration of same-place voiceless fricatives was higher than voiced fricatives both in voiced and whispered speech. The evidence presented in this paper can be used to restore voiced speech signals, and to inform rehabilitation strategies that can safely explore the production mechanisms of whispering.

Measuring second language acquisition of spanish lenition

In intervocalic position, Spanish /b/, /d/, and /g/ are lenited to fricatives or approximants [β], [ð], and [ɣ] (Hualde 2005).The goal of this study is to examine the ability to learn allophones of these Spanish voiced stops among L2 learners. Eighteen native English-speaking Spanish learners were recorded reading word lists at the beginning and end of a semester-long course on Spanish pronunciation, which included explicit instruction on voiced stop allophones. Ennever, Meakins, and Round (2017)’s automatic segmentation method was used to analyze degree of lenition. This method uses the intensity contour to determine the on- and offset of intervocalic consonants. It yields three measurements: difference between maximum and minimum intensity (Δi), maximum change in intensity over time, i.e. velocity, (vpeak) and duration. A smaller absolute value of Δi and vpeak, and a shorter duration correspond with a greater degree of lenition. Between the two recording times, Δi, vpeak, and duration all decreased, demonstrating some learning of Spanish lenition. Results on the impact of preceding and following vowels, and consonant place of articulation were mixed. Syllable stress and age of onset of Spanish instruction had no effect on lenition.

Articulatory Underpinnings of Reduced Acoustic-Phonetic Contrasts in Individuals With Amyotrophic Lateral Sclerosis.

The aim of this study is to identify the articulatory underpinnings of the acoustic-phonetic correlates of functional speech decline in individuals with amyotrophic lateral sclerosis (ALS). Thirteen individuals with varying severities of speech impairment secondary to ALS and 10 neurologically healthy controls speakers read 12 minimal word pairs, targeting the contrasts in the height, advancement, and length of vowels; the manner and place of articulation for consonants and consonant cluster; and liquid and glide approximants, 5 times. Sixteen acoustic features were extracted to characterize the phonetic contrasts of these minimal word pairs. These acoustic features were correlated with a functional speech index-intelligible speaking rate-using penalized regression, based on which the contributive features were identified as the acoustic-phonetic correlates of the functional speech outcome. Articulatory contrasts of the minimal word pairs were characterized by a set of dissimilarity indices derived by the dynamic time warping algorithm, which measured the differences in the displacement and velocity trajectories of tongue tip, tongue dorsum, lower lip, and jaw between the minimal word pairs. The contributive articulatory features to the acoustic-phonetic correlates were identified by penalized regression. A variety of acoustic-phonetic features were identified as contributing to the functional speech outcome, of which the contrasts in vowel height and advancement, [r]-[l], [r]-[w], and initial cluster-singleton were the most affected in individuals with ALS. Differential articulatory underpinnings were identified for these acoustic-phonetic features. Impairments of these articulatory underpinnings, especially of tongue tip and tongue dorsum velocities and tongue tip displacement, were associated with reduced acoustic-phonetic contrasts of the minimal word pairs, in a context-specific manner. The findings established explanatory relationships between articulatory impairment and the acoustic-phonetic profile of functional speech decline in ALS, providing useful information for developing targeted management strategies to improve and prolong functional speech in individuals with ALS.

Phonetic Effects in the Perception of VOT in a Prevoicing Language.

Previous production studies have reported differential amounts of closure voicing in plosives depending on the location of the oral constriction (anterior vs. posterior), vocalic context (high vs. low vowels), and speaker sex. Such differences have been attributed to the aerodynamic factors related to the configuration of the cavity behind the oral constriction, with certain articulations and physiological characteristics of the speaker facilitating vocal fold vibration during closure. The current study used perceptual identification tasks to examine whether similar effects of consonantal posteriority, adjacent vowel height, and speaker sex exist in the perception of voicing. The language of investigation was Russian, a prevoicing language that uses negative VOT to signal the voicing contrast in plosives. The study used both original and resynthesized tokens for speaker sex, which allowed it to focus on the role of differences in VOT specifically. Results indicated that listeners’ judgments were significantly affected by consonantal place of articulation, with listeners accepting less voicing in velar plosives. Speaker sex showed only a marginally significant difference in the expected direction, and vowel height had no effect on perceptual responses. These findings suggest that certain phonetic factors can affect both the initial production and subsequent perception of closure voicing.

Phonetic Characteristics of Children's Early Words in German: Data From Typically Developing Children With Clinical Implications

Purpose:This study examined sound sequencing characteristics of German children's early words to compare with the patterns established for American English. We focused on consonant place of articulation for comparative purposes to Aoyama and Davis (2017) on children acquiring American English. Consonant–vowel–consonant (C1VC2) word forms is a frequent clinical target area for children receiving speech intervention for delays or disorders. Our goal is to provide useful background information for clinical decisions with German-speaking children.Method:Data from 13 German-speaking children were analyzed using the Child Language Data Exchange System database. First and second consonants in C1VC2word forms were coded as a labial (e.g., /p/, /b/, /m/), a coronal (alveolar and palatal, e.g., /t/, /d/, /n/), or a dorsal (velar, e.g., /k/, /g/, /ŋ/). All word types and tokens were then categorized into nine place–sequence types (e.g., labial–labial, Baum /baʊm/ “tree”; labial–coronal, mit /mɪt/ “with”; labial–velar, Weg /vɛk/ “path”).Results:C1VC2words consisting of labial–coronal and coronal–coronal sequences occurred more frequently than other sequences (e.g., labial–labial, coronal–labial). Words with labial–coronal sequences were much more frequent than the opposite coronal–labial sequences, similar to English. Some sequences involving dorsals (i.e., dorsal–labial) are relatively frequent in German words compared to English words.Conclusions:Results demonstrated both similarities and differences with previous studies of typically developing children learning American English. In both German and English, labial–coronal and coronal–coronal sequences were by far the most frequent. Sequences involving dorsal consonants were more frequent in German than in English. For clinical planning, results suggest that place-of-articulation patterns in C1VC2words are similar between German and English words (e.g., high frequencies of labial–coronal and coronal–coronal sequences). However, sequences involving dorsals are more frequent in German than in English. For intervention, this information can be used to guide selection of words containing sound sequences that are frequent for German-speaking children.

Auditory Perception and Production of Speech Feature Contrasts by Pediatric Implant Users

The aim of the present research is to examine the relations between auditory perception and production of specific speech contrasts by children with cochlear implants (CIs) who received their implants before 3 years of age and to examine the hierarchy of abilities for perception and production for consonant and vowel features. The following features were examined: vowel height, vowel place, consonant place of articulation (front and back), continuance, and consonant voicing. Fifteen children (mean age = 4;0 and range 3;2 to 5;11) with a minimum of 18 months of experience with their implants and no additional known disabilities served as participants. Perception of feature contrasts was assessed using a modification of the Online Imitative Speech Pattern Contrast test, which uses imitation to assess speech feature perception. Production was examined by having the children name a series of pictures containing consonant and vowel segments that reflected contrasts of each feature. For five of the six feature contrasts, production accuracy was higher than perception accuracy. There was also a significant and positive correlation between accuracy of production and auditory perception for each consonant feature. This correlation was not found for vowels, owing largely to the overall high perception and production scores attained on the vowel features. The children perceived vowel feature contrasts more accurately than consonant feature contrasts. On average, the children had lower perception scores for Back Place and Continuance feature contrasts than for Anterior Place and Voicing contrasts. For all features, the median production scores were 100%; the majority of the children were able to accurately and consistently produce the feature contrasts. The mean production scores for features reflect greater score variability for consonant feature production than for vowel features. Back Place of articulation for back consonants and Continuance contrasts appeared to be the most difficult features to produce, as reflected in lower mean production scores for these features. The finding of greater production than auditory perception accuracy for five of the six features examined suggests that the children with CIs were able to produce articulatory contrasts that were not readily perceived through audition alone. Factors that are likely to play a role in the greater production accuracy in addition to audition include the lexical and phonetic properties of the words elicited, a child's phonological representation of the words and motor abilities, and learning through oro-tactile, visual, proprioceptive, and kinesthetic perception. The differences among the features examined, and between perception and production, point to the clinical importance of evaluating these abilities in children with CIs. The present findings further point to the utility of picture naming to establish a child's production accuracy, which in turn is necessary if using imitation as a measure of auditory capacity.

The emergence of phonetic–phonological features in a biologically inspired model of speech processing

Because speech acquisition begins with sensorimotor activity (i.e. babbling and imitation of speech items in order to learn articulatory–acoustic relations) as well as with semantic cognitive processing (i.e. linking phonetic items with concepts), distinctiveness as well as phonetic–phonological features emerge early in speech acquisition. Based on a biologically inspired model of speech processing, using interconnected growing self-organizing maps (I-GSOMs), the phonetic–phonological interface is described here in terms of a numerical computer-implemented model. By simulating early phases of speech acquisition, it can be shown that vocalic features like low–high as well as consonantal features describing the manner of articulation (like plosive, fricative, nasal, lateral, etc.) already arise at sensorimotor levels. This is reflected in our model by an ordering of syllables with respect to phonetic–phonological features at the level of an auditory based neural map. Other features like consonantal place of articulation (labial, apical, dorsal) as well as voiced–voiceless emerge at higher levels within our model, i.e. at the level of neural associations between a phonetic and a semantic neural map. It can be hypothesized from these findings that the phonetic–phonological interface does not appear as a clean cut within the speech processing system but as a broader zone within that system located between sensorimotor and semantic processing.

Accounting for variability in North American English /ɹ/: Evidence from children's articulation

This acoustic and articulatory pilot study examines the North American English /ɹ/ productions of English-speaking children during acquisition, and compares their early- and later-stage productions with /ɹ/ allophony patterns reported in previous studies with adults. Ultrasound imaging is used to investigate the articulatory behavior of four children, aged 3–6 years, during production of familiar lexical items containing prevocalic, post-vocalic, and syllabic /ɹ/. Shape analysis of the tongue is conducted using a technique that is highly robust against rotational and translational differences from token to token. Participants exhibited behaviors that are consistent with adults' in previous studies, showing both intra- and inter-speaker variability, and similar patterns of allophony based on syllable position, consonant place of articulation, and vowel quality. For three participants, variable behavior occurred prevocalically, in contexts where adults tend to exhibit the greatest amount of allophonic variation. Variable behavior during acquisition of an articulatorily complex speech sound provides a plausible explanation for the variability that has been previously reported with adults. If a child's dominant strategy for reaching adult-like targets proves ineffective in certain contexts, that may motivate exploratory behavior that could lead to a stable alternative strategy in those contexts over time. Participants' later-stage productions mirror allophony patterns observed with adults in previous studies. The current research adds to the literature on children's articulatory behavior during acquisition, and to the body of accumulated knowledge on North American English /ɹ/.

Place contrast enhancement: The case of the alveolar and retroflex sibilant production in two dialects of Mandarin

While segmental contrasts are under prosodically strong conditions, acoustic properties encoding the contrastive features are generally exaggerated, which gives rise to phonological enhancement. One exception that previous research found for such prosodic effects is on consonantal place of articulation (Cole, Kim, Choi, & Hasegawa-Johnson, 2007; Silbert & de Jong, 2008). Whether this is an issue of the nature of the segments under study, or a language-specific phenomenon is worth further investigation. This paper builds on Chuang and Fon's (2010) study of Taiwan Mandarin alveolar and retroflex sibilants and extends the examination to another dialect of Mandarin, Beijing Mandarin. With a series of map tasks to elicit natural yet well-controlled data, this study asks whether contrastive focus realizations of the alveolar–retroflex contrast vary across vowel contexts between the two dialects. Results show that, consistent with Silbert and de Jong's finding for place distinction in English fricatives, focal prominence may result in the exaggeration of non-contrastive dimensions (i.e., longer syllable and frication duration as well as higher frication amplitude) without enhancing feature-defining properties (i.e., a greater acoustic distance between alveolar and retroflex sibilants). It is suggested that the place feature, particularly in coronal sibilants, is generally less subject to cue-enhancing hyperarticulation, regardless of languages and dialects.

Effects of vowel position and place of articulation on voice onset time in children: Longitudinal data

Voice onset time (VOT) has been found to vary according to phonetic context, but past studies report varying magnitudes of effect, and no past work has evaluated the degree to which such effects are consistent over time for a single speaker. This study explores the relationships between vowel position, consonant place of articulation [POA], and voice onset time (VOT) in children, comparing the results to past adult work. VOT in CV/CVC words was measured in nine children ages 5;3–7;6 every two-four weeks for 10 months, for a total of 18 sessions yielding approximately 18,000 tokens for analysis. Bilabial and velar cognate pairs targeted a front-back vowel difference (/i/-/u/, /e/-/o/), while alveolar cognate pairs targeted a mid high-low vowel difference (/o/-/ɑ/). VOT variability over time was also evaluated. Preliminary results suggest that POA yields a robust pattern of bilabial < alveolar < velar, but vowel effects are less clear. Vowel height shows the most obvious effect with consistently longer VOT values observed for mid high vowels. Front-back vowel comparisons yielded no obvious differences. On the whole, contextual variations based on POA and vowel context do not show clear correlations with overall VOT variation.

Analysis and Recognition of Arabic Consonants Using Locus Equations

 Abstract—The acoustic measurement of articulation place for consonants and the acoustic measurement of the amount of coarticulation are two long-standing problems in phonetics. Previous work on consonant place of articulation, using articulatory-acoustic models, within the acoustic theory of speech production (Stevens, 1998), has found certain acoustic correlates of place, but the variability found in empirically-based studies has not provided an easy match to the theoretical predictions. This study is to analyze the precision with which locus equations determine the place of articulation for both Arabic plosives / q / (/ق /) and /? / (/ء/) and the two fricatives / ʕ / (/ع/) and / h / (/ه/), where these are preceded by the front vowel /u / and posterior vowel /i/ with respect the middle vowel /a/. The results helped to make the distinction (or classification) of these four phonemes by locus equation.

Locus equations and the place of articulation for the Latvian sonorants

In the article, the sonorant consonants of Standard Latvian are investigated using locus equations. The aim of the study is to examine whether locus equations can be considered as efficient descriptors of consonantal place of articulation both within the group of sonorants and across different manner classes in Standard Latvian. Two-type sequences were analyzed: (1) the CV part of isolated nonsense CVC syllables, where C is one of the sonorants [m; n; ɲ; l; ʎ; r] and V is one of the vowels [i(ː); e(ː); ae(ː); ɑ(ː); ɔ(ː); u(ː)]; (2) the V(ː)C part of isolated nonsense V(ː)CV (VCV for [ŋ]) structure utterances, where C is one of the nasals [m; n; ɲ; ŋ] and V is one of the vowels [i; e; ae; ɑ; ɔ; u]. Each utterance was recorded in three repetitions by every of 10 native Latvian speakers (five males and five females), thus 3420 items were analyzed in total. Statistical analysis of locus equation slopes and y-intercepts both for the sonorants and for the whole consonant inventory of Standard Latvian was performed in order to test the relevance of these indices for discriminating places of articulation across different manner classes. By plotting the data for the whole consonant inventory in slope-by-intercept space it is possible to distinguish between the groups of palatals/dentals/alveolars and labials/velars, while the results of statistical analysis show significant difference among all place categories. According to the results, there are certain coarticulatory mechanisms associated with particular places of constriction for the Latvian consonants that allow linking locus equation data to different place categories, although they are also affected by manner and voicing. Nevertheless, place of articulation as a determinant of coarticulatory patterns overrules these factors when other possible influences are excluded.

Classification of affricate burst place in consonant-vowel contexts in English

This study investigates characteristics of affricate burst place of articulation compared with the bursts for the three places of articulation for stops (labial, alveolar, and velar) in English. The data comprise consonant-vowel tokens in the TIMIT corpus. To assess which stop place of articulation may be used to simultaneously model affricate bursts, Jensen-Shannon divergence measures are found for probability distributions of acoustic-phonetic features. In addition, we conduct classification experiments using combinations of acoustic-phonetic features and Mel-frequency cepstral coefficients (MFCCs), to see how well affricate burst place is classified using models for the three stop places. The experimental results show that although affricate place is similar to the alveolar place of articulation for stops, a separate post-alveolar place for affricate burst provides a better model. The results suggest that a separate affricate place model will be useful in a feature-based speech recognition system that explicitly detects place of articulation for consonants.

Refining bouba-kiki: Phonetic detail and object dimensionality in sound-shape correspondences

Speakers cross-linguistically associate non-words that have round vowels, such as /buba/, with round shapes, and non-words without round vowels, such as /kike/, with spiky shapes (e.g. Kohler 1947). While this link has been attributed to cognitive associations between rounded vowel sounds and images of rounded lips, stimuli have conflated vowel roundness with other phonetic features that may also contribute to the correspondence. In this study, 200 listeners matched abstract objects with nonsense words that systematically varied by vowel frontness, consonant place of articulation, and consonant voicing. Listeners are significantly more likely to select a spiky shape over a round shape when given words with voiceless consonants, alveolar consonants, and front vowels; combinations of these features strengthen the effect. These findings are corroborated in the realm of real-world objects. 102 participants were more likely to name a rounded member of a real-world object class when hearing a word containing non-front vowels than when hearing a word containing front vowels. Further, two- versus three-dimensional object roundness influences the strength of this association. This study provides an empirically and phonetically refined perspective on the paradigm, demonstrating the benefit of considering both detailed phonetic correlates and refined object properties in work on sound symbolism.

Use of waveform mixing to synthesize a continuum of vowel nasality in natural speech

Studies of the perception of vowel nasality often use synthesized stimuli to produce controlled gradience in nasality. To investigate the perception of nasality in natural speech, a method was developed wherein vowels differing naturally in nasality (e.g., from CVC and NVN words) are mixed to yield tokens with various degrees of nasality. First, monosyllables (e.g., CVC, NVC, CVN, NVN) matched for vowel quality and consonant place of articulation were recorded. The vowels from two tokens were excised, matched for amplitude, duration and pitch contour, and then overlaid sample-by-sample according to a specified ratio. The resulting vowel was spliced back into the desired consonantal context. Iterating this process over a series of ratios produced natural-sounding tokens along a continuum of vowel nasality. Acoustic measurements of the nasality of output tokens [using A1-P0 (Chen, 1997)] confirmed a relation between the ratio used and the nasality of the output. Stimuli created in this manner were used in a perception experiment (Scarborough etal., 2011) where degree of nasality affected perception without any slowdown in response time for nasality-altered vs. unaltered tokens. This demonstrates the quality of the nasal-altered stimuli and suggests the potential usefulness of this process for other speech perception studies.

Intracranial Study of Speech-Elicited Activity on the Human Posterolateral Superior Temporal Gyrus

To clarify speech-elicited response patterns within auditory-responsive cortex of the posterolateral superior temporal (PLST) gyrus, time-frequency analyses of event-related band power in the high gamma frequency range (75-175 Hz) were performed on the electrocorticograms recorded from high-density subdural grid electrodes in 8 patients undergoing evaluation for medically intractable epilepsy. Stimuli were 6 stop consonant-vowel (CV) syllables that varied in their consonant place of articulation (POA) and voice onset time (VOT). Initial augmentation was maximal over several centimeters of PLST, lasted about 400 ms, and was often followed by suppression and a local outward expansion of activation. Maximal gamma power overlapped either the Nα or Pβ deflections of the average evoked potential (AEP). Correlations were observed between the relative magnitudes of gamma band responses elicited by unvoiced stop CV syllables (/pa/, /ka/, /ta/) and their corresponding voiced stop CV syllables (/ba/, /ga/, /da/), as well as by the VOT of the stimuli. VOT was also represented in the temporal patterns of the AEP. These findings, obtained in the passive awake state, indicate that PLST discriminates acoustic features associated with POA and VOT and serve as a benchmark upon which task-related speech activity can be compared.

Within-Subjects Comparison of the HiRes and Fidelity120 Speech Processing Strategies: Speech Perception and Its Relation to Place-Pitch Sensitivity

Previous studies have confirmed that current steering can increase the number of discriminable pitches available to many cochlear implant (CI) users; however, the ability to perceive additional pitches has not been linked to improved speech perception. The primary goals of this study were to determine (1) whether adult CI users can achieve higher levels of spectral cue transmission with a speech processing strategy that implements current steering (Fidelity120) than with a predecessor strategy (HiRes) and, if so, (2) whether the magnitude of improvement can be predicted from individual differences in place-pitch sensitivity. A secondary goal was to determine whether Fidelity120 supports higher levels of speech recognition in noise than HiRes. A within-subjects repeated measures design evaluated speech perception performance with Fidelity120 relative to HiRes in 10 adult CI users. Subjects used the novel strategy (either HiRes or Fidelity120) for 8 wks during the main study; a subset of five subjects used Fidelity120 for three additional months after the main study. Speech perception was assessed for the spectral cues related to vowel F1 frequency, vowel F2 frequency, and consonant place of articulation; overall transmitted information for vowels and consonants; and sentence recognition in noise. Place-pitch sensitivity was measured for electrode pairs in the apical, middle, and basal regions of the implanted array using a psychophysical pitch-ranking task. With one exception, there was no effect of strategy (HiRes versus Fidelity120) on the speech measures tested, either during the main study (N = 10) or after extended use of Fidelity120 (N = 5). The exception was a small but significant advantage for HiRes over Fidelity120 for consonant perception during the main study. Examination of individual subjects' data revealed that 3 of 10 subjects demonstrated improved perception of one or more spectral cues with Fidelity120 relative to HiRes after 8 wks or longer experience with Fidelity120. Another three subjects exhibited initial decrements in spectral cue perception with Fidelity120 at the 8-wk time point; however, evidence from one subject suggested that such decrements may resolve with additional experience. Place-pitch thresholds were inversely related to improvements in vowel F2 frequency perception with Fidelity120 relative to HiRes. However, no relationship was observed between place-pitch thresholds and the other spectral measures (vowel F1 frequency or consonant place of articulation). Findings suggest that Fidelity120 supports small improvements in the perception of spectral speech cues in some Advanced Bionics CI users; however, many users show no clear benefit. Benefits are more likely to occur for vowel spectral cues (related to F1 and F2 frequency) than for consonant spectral cues (related to place of articulation). There was an inconsistent relationship between place-pitch sensitivity and improvements in spectral cue perception with Fidelity120 relative to HiRes. This may partly reflect the small number of sites at which place-pitch thresholds were measured. Contrary to some previous reports, there was no clear evidence that Fidelity120 supports improved sentence recognition in noise.

Enhanced physiologic discriminability of stop consonants with prolonged formant transitions in awake monkeys based on the tonotopic organization of primary auditory cortex

Many children with specific language impairment (SLI) have difficulty in perceiving stop consonant-vowel syllables (e.g., /ba/, /ga/, /da/) with rapid formant transitions, but perform normally when formant transitions are extended in time. This influential observation has helped lead to the development of the auditory temporal processing hypothesis, which posits that SLI is causally related to the processing of rapidly changing sounds in aberrantly expanded windows of temporal integration. We tested a potential physiological basis for this observation by examining whether syllables varying in their consonant place of articulation (POA) with prolonged formant transitions would evoke better differentiated patterns of activation along the tonotopic axis of A1 in awake monkeys when compared to syllables with short formant transitions, especially for more prolonged windows of temporal integration. Amplitudes of multi-unit activity evoked by /ba/, /ga/, and /da/ were ranked according to predictions based on responses to tones centered at the spectral maxima of frication at syllable onset. Population responses representing consonant POA were predicted by the tone responses. Predictions were stronger for syllables with prolonged formant transitions, especially for longer windows of temporal integration. Relevance of findings to normal perception and that occurring in SLI are discussed.

On the relation between locus equations and subglottal resonances.

In consonant‐vowel transitions, it is well known that the frequency of the second formant at the onset of voicing (F2onset) is linearly correlated with the frequency of the second formant in the middle of the vowel (F2vowel). This correlation, which holds across the vowel contexts for a given consonant place of articulation (POA), is characterized by a regression line (locus equation) with a slope and y‐intercept that depend on the consonant POA. Furthermore, for a given POA, slopes and y‐intercepts of collections of locus equations are inversely related. The cause of this inverse relation has not yet been explained. In this presentation, we will show that the inverse relation implies that the F2vowel vs. F2onset coordinate system is most naturally described as a mathematical translation away from the origin, and that the size of the translation is a function of the POA and of the second and third subglottal resonances.