Perception Of Syllables Research Articles

How canaries listen to their song

Canaries have become important models for the study of vocal learning. The male produces long song bouts up to a minute long consisting of various syllables, each repeated in flexibly sequenced phrases. Little is known about how the birds listen to song though behavioral observations clearly show that female canaries are more sexually responsive to a special song element—so called “sexy” syllables—which are distinguished by a high syllable repetition rate, wide-bandwidth, and multiple notes. Here, operant conditioning and psychophysical techniques were used to determine the discriminability of variation in syllable and phrase morphology. Results show that canaries can discriminate the subtle differences among syllables and phrases using spectral, envelope, and temporal fine structure cues but they are no better than budgerigars used as controls. There was also evidence that perception of sexy syllables is distinctive for canaries. On the whole, while canaries can hear the fine details of the acoustic structure of their song, the evidence suggests that they listen at a more synthetic rather than analytic level. These results give clues to how the canary perceptual system may be shaped to process male song and make judgments about mate quality.

Infant Diet-Related Changes in Syllable Processing Between 4 and 5 Months: Implications for Developing Native Language Sensitivity

Since maturational processes triggering increased attunement to native language features in early infancy are sensitive to dietary factors, infant-diet related differences in brain processing of native-language speech stimuli might indicate variations in the onset of this tuning process. We measured cortical responses (ERPs) to syllables in 4 and 5 month old infants fed breast milk, milk formula, or soy formula and found syllable discrimination (P350) and syntactic-related functions (P600) but not syllable perception (P170) varied by diet, but not gender or background measures. The results suggest breastfed and formula-fed infants differ in onset of this critical period in speech perception.

Selective adaptation of crossmodal speech information is not the result of higher-level stimulus associations

Selective adaptation of speech information can change perceptual categorization of ambiguous phonetic information (e.g., Vroomen and Baart, 2012). The results of a number of studies suggest that selective adaptation may depend on sensory-specific information shared between the adaptor and test stimuli (e.g., Roberts and Summerfield, 1981; Saldaña and Rosenblum, 1994). For example, adaptation to heard syllables can change perception of heard syllables, but adaptation to lipread syllables has not been found to significantly change perception of heard syllables. The lack of crossmodal influence in selective speech adaptation is inconsistent with other phenomena suggesting crossmodal influences occur early in the speech process (e.g., Rosenblum, 2008). For the current investigation, a replication of an attempt to induce crossmodal speech adaptation again failed to yield significant effects. However, a meta-analysis including these results with past attempts (Roberts and Summerfield, 1981) revealed that small crossmodal speech adaptation effects are significant across studies. Next, an attempt to induce crossmodal speech adaptation employing a much larger group of new participants did yield significant crossmodal adaptation effects. A replication using text-stimuli failed to induce similar adaptation effects, suggesting that the observed crossmodal effects are not the result of higher-level stimulus associations. The theoretical implications of these smaller crossmodal effects will be discussed.

Clear speech benefits for perception of center-only and edge-only syllables

Clear speech is a speaking style that has been shown to enhance intelligibility in noise; however, the underlying reasons for this enhancement are less well understood. One hypothesis is that listeners require less acoustic information to identify syllables spoken in clear than in conversational speech, allowing them to make use of briefer dips in fluctuating noise. The present study tests this hypothesis by presenting six /bVd/ syllables (“bead, bid, bed, bayed, bad,” and “bod”), produced in clear and conversational speech styles, to 20 monolingual native English-speaking listeners in a six-alternative forced-choice task. These syllables were modified to present varying portions of the syllable to listeners (20, 40, 60, or 80 ms of the syllable preserved). First, center-only syllables were created, in which acoustic information around the vowel midpoint was preserved. Second, edge-only syllables were created, in which information from the vowel center was silenced and formant transitions preserved, with ...

Changed categorical perception of consonant-vowel syllables induced by transcranial direct current stimulation (tDCS).

BackgroundSpeech-related disorders may refer to impairment of temporal analysis in the human auditory system. By the advance of non-invasive brain stimulation new forms of therapy arise. In the present study, we examined the neuromodulatory effect of auditory tDCS on the perception of temporal modulated speech syllables. In three experimental sessions we assessed phonetic categorization of consonant–vowels (CV)-syllables (/da/,/ta/) with varying voice onset times (VOT) during sham, anodal, and cathodal tDCS delivered bilateral to the auditory cortex (AC). Subsequently, we recorded auditory evoked potentials (AEP) in response to voiced (/ba/,/da/,/ga/) and voiceless (/pa/,/ta/,/ka/) CV-syllables.ResultsIn result, we demonstrate that bilateral tDCS of the AC can modulate CV-syllable perception. Behaviorally, cathodal tDCS improved phonetic categorization abilities in a VOT continuum accompanied by an elevation of the P50 amplitude of the AEP to CV-syllables during the anodal tDCS after effect.ConclusionsThe present study demonstrates the ability of bilateral tDCS over the AC to ameliorate speech perception. The results may have clinical implications by fostering potential approaches for a treatment of speech-related pathologies with a deficit of temporal processing.

The Effect of Peripheral Compression on Syllable Perception Measured with a Hearing Impairment Simulator.

Hearing impaired (HI) people often have difficulty understanding speech in multi-speaker or noisy environments. With HI listeners, however, it is often difficult to specify which stage, or stages, of auditory processing are responsible for the deficit. There might also be cognitive problems associated with age. In this paper, a HI simulator, based on the dynamic, compressive gammachirp (dcGC) filterbank, was used to measure the effect of a loss of compression on syllable recognition. The HI simulator can counteract the cochlear compression in normal hearing (NH) listeners and, thereby, isolate the deficit associated with a loss of compression in speech perception. Listeners were required to identify the second syllable in a three-syllable "nonsense word", and between trials, the relative level of the second syllable was varied, or the level of the entire sequence was varied. The difference between the Speech Reception Threshold (SRT) in these two conditions reveals the effect of compression on speech perception. The HI simulator adjusted a NH listener's compression to that of the "average 80-year old" with either normal compression or complete loss of compression. A reference condition was included where the HI simulator applied a simple 30-dB reduction in stimulus level. The results show that the loss of compression has its largest effect on recognition when the second syllable is attenuated relative to the first and third syllables. This is probably because the internal level of the second syllable is attenuated proportionately more when there is a loss of compression.

The role of tone in Chinese syllable perception

The role of tone in Chinese syllable perception

Oscillatory phase shapes syllable perception

The role of oscillatory phase for perceptual and cognitive processes is being increasingly acknowledged. To date, little is known about the direct role of phase in categorical perception. Here we show in two separate experiments that the identification of ambiguous syllables that can either be perceived as /da/ or /ga/ is biased by the underlying oscillatory phase as measured with EEG and sensory entrainment to rhythmic stimuli. The measured phase difference in which perception is biased toward /da/ or /ga/ exactly matched the different temporal onset delays in natural audiovisual speech between mouth movements and speech sounds, which last 80 ms longer for /ga/ than for /da/. These results indicate the functional relationship between prestimulus phase and syllable identification, and signify that the origin of this phase relationship could lie in exposure and subsequent learning of unique audiovisual temporal onset differences.

Why repetition? Repetitive babbling, auditory feedback, and cochlear implantation

This study investigated the reduplicated, or repetitive vocalizations of hearing infants and infants with profound hearing loss with and without cochlear implants using a new measure of repetition in order to address questions not only about the effects of cochlear implantation on repetitive babbling, but also about the reason repetitive vocalizations occur at all and why they emerge around 7 or 8months of age in hearing infants. Participants were 16 infants with profound hearing loss and 27 hearing infants who participated at a mean age of 9.9months and/or a mean age of 17.7months. Mean age at cochlear implantation for infants with profound hearing loss was 12.9months, and mean duration of implant use was 4.2months. The data show that before cochlear implantation, repetitive vocalizations were rare. However, 4months after cochlear implant activation, infants with hearing loss produced both repetitive vocalizations and repetitions per vocalization at levels commensurate with their hearing peers. The results support the hypothesis that repetition emerges as a means of vocal exploration during the time when hearing infants (and infants with cochlear implants) form auditory–motor representations and neural connections between cortical areas active in syllable production and syllable perception, during the transition from nonlinguistic to linguistic vocalization.

An approach to the analysis of relations between syllable and sentence perception in quiet and noise in the Speech Perception Assessment and Training System: Preliminary results for ten hearing-aid users

Logistic functions relating abilities to indentify syllable onsets, nuclei, and codas in quiet and noise as a function of snr are measured. Syllable perception is the product of these individual abilities. It is found that syllable perception in noise is highly correlated with syllable perception quiet. The relation of sentence perception in the SPATS sentence task with SPATS syllable constituent perception is examined. As shown years ago at the Bell Labs, only modest levels of syllable identification are needed to support nearly perfect levels of sentence perception. Here, it is found that sentence perception in quiet and noise is correlated with syllable perception in quiet, the use of inherent context provided by syllable perception (Boothroyd and Nittrauer (1988)), and with the use of situational context, independent of syllable perception. Finally, the effects of speech perception training on these relations are examined for each of the ten hearing-aid users studied. [Work supported by NIH/NICD Grant...

Processing of speech temporal and spectral information by users of auditory brainstem implants and cochlear implants.

Auditory brainstem implants (ABI) use the same processing strategy as was developed for cochlear implants (CI). However, the cochlear nucleus (CN), the stimulation site of ABIs, is anatomically and physiologically more complex than the auditory nerve and consists of neurons with differing roles in auditory processing. The aim of this study was to evaluate the hypotheses that ABI users are less able than CI users to access speech spectro-temporal information delivered by the existing strategies and that the sites stimulated by different locations of CI and ABI electrode arrays differ in encoding of temporal patterns in the stimulation. Six CI users and four ABI users of Nucleus implants with ACE processing strategy participated in this study. Closed-set perception of aCa syllables (16 consonants) and bVd words (11 vowels) was evaluated via experimental processing strategies that activated one, two, or four of the electrodes of the array in a CIS manner as well as subjects' clinical strategies. Three single-channel strategies presented the overall temporal envelope variations of the signal on a single-implant electrode located at the high-, medium-, and low-frequency regions of the array. Implantees' ability to discriminate within electrode temporal patterns of stimulation for phoneme perception and their ability to make use of spectral information presented by increased number of active electrodes were assessed in the single- and multiple-channel strategies, respectively. Overall percentages and information transmission of phonetic features were obtained for each experimental program. Phoneme perception performance of three ABI users was within the range of CI users in most of the experimental strategies and improved as the number of active electrodes increased. One ABI user performed close to chance with all the single and multiple electrode strategies. There was no significant difference between apical, basal, and middle CI electrodes in transmitting speech temporal information, except a trend that the voicing feature was the least transmitted by the basal electrode. A similar electrode-location pattern could be observed in most ABI subjects. Although the number of tested ABI subjects was small, their wide range of phoneme perception performance was consistent with previous reports of overall speech perception in ABI patients. The better-performing ABI user participants had access to speech temporal and spectral information that was comparable to that of average CI user. The poor-performing ABI user did not have access to within-channel speech temporal information and did not benefit from an increased number of spectral channels. The within-subject variability between different ABI electrodes was less than the variability across users in transmission of speech temporal information. The difference in the performance of ABI users could be related to the location of their electrode array on the CN, anatomy, and physiology of their CN or the damage to their auditory brainstem due to tumor or surgery.

Different Neural Networks Are Involved in Audiovisual Speech Perception Depending on the Context

How are we able to easily and accurately recognize speech sounds despite the lack of acoustic invariance? One proposed solution is the existence of a neural representation of speech syllable perception that transcends its sensory properties. In the present fMRI study, we used two different audiovisual speech contexts both intended to identify brain areas whose levels of activation would be conditioned by the speech percept independent from its sensory source information. We exploited McGurk audiovisual fusion to obtain short oddball sequences of syllables that were either (a) acoustically different but perceived as similar or (b) acoustically identical but perceived as different. We reasoned that, if there is a single network of brain areas representing abstract speech perception, this network would show a reduction of activity when presented with syllables that are acoustically different but perceived as similar and an increase in activity when presented with syllables that are acoustically similar but perceived as distinct. Consistent with the long-standing idea that speech production areas may be involved in speech perception, we found that frontal areas were part of the neural network that showed reduced activity for sequences of perceptually similar syllables. Another network was revealed, however, when focusing on areas that exhibited increased activity for perceptually different but acoustically identical syllables. This alternative network included auditory areas but no left frontal activations. In addition, our findings point to the importance of subcortical structures much less often considered when addressing issues pertaining to perceptual representations.

Multimodal integration in statistical learning: evidence from the McGurk illusion.

Recent advances in the field of statistical learning have established that learners are able to track regularities of multimodal stimuli, yet it is unknown whether the statistical computations are performed on integrated representations or on separate, unimodal representations. In the present study, we investigated the ability of adults to integrate audio and visual input during statistical learning. We presented learners with a speech stream synchronized with a video of a speaker’s face. In the critical condition, the visual (e.g., /gi/) and auditory (e.g., /mi/) signals were occasionally incongruent, which we predicted would produce the McGurk illusion, resulting in the perception of an audiovisual syllable (e.g., /ni/). In this way, we used the McGurk illusion to manipulate the underlying statistical structure of the speech streams, such that perception of these illusory syllables facilitated participants’ ability to segment the speech stream. Our results therefore demonstrate that participants can integrate audio and visual input to perceive the McGurk illusion during statistical learning. We interpret our findings as support for modality-interactive accounts of statistical learning.

Perception of conversational and clear speech syllables by native and non-native English-speaking listeners

In a recent study later, but not earlier, learners of English as a second language produced a smaller clear-speech benefit than native English-speaking talkers for vowels produced in six /bVd/ syllables (Rogers et al., 2010, JASA 123, 410–423). The present study compares perception of the same syllables by native and non-native English-speaking listeners. Conversational and clear-speech productions of the target syllables, “bead, bid, bayed, bed, bad,” and “bod,” were selected from three monolingual English speakers who had produced a significant clear-speech benefit in Rogers et al. (2010). The syllables were then mixed with noise at several signal-to-noise ratios (SNRs). Perception of these stimuli by three groups of listeners will be examined: (1) monolingual native English speakers, (2) ‘early’ learners of English as a second language, with an age of immersion (AOI) of 12 or earlier, and (3) later learners of English as a second language, with an AOI of 15 or later. Analyses of results of the six-alternative forced-choice task will focus on comparisons across listener groups, for the following measures: (1) estimates of clear-speech benefit at approximately 50% correct; (2) performance at a common SNR; and (3) estimates of the slope of the psychometric function. [Work supported by NIH.]

Speech Compensation for Time-Scale-Modified Auditory Feedback

PURPOSE The purpose of this study was to examine speech compensation in response to time-scale-modified auditory feedback during the transition of the semivowel for a target utterance of /ija/. METHOD Each utterance session consisted of 10 control trials in the normal feedback condition followed by 20 perturbed trials in the modified auditory feedback condition and 10 return trials in the normal feedback condition. The authors examined speech compensation and the aftereffect in terms of 3 acoustic features: the maximum velocities on the (a) F1 and (b) F2 trajectories (VF1 and VF2) and (c) the F1-F2 onset time difference (TD) during the transition. They also conducted a syllable perception test on the feedback speech. RESULTS Speech compensation was observed in VF1, VF2, and TD. The magnitudes of speech compensation in VF1 and TD monotonically increased as the amount of the time-scale perturbation increased. The amount of speech compensation increased as the phonemic perception change increased. CONCLUSIONS Speech compensation for time-scale-modified auditory feedback is carried out primarily by changing VF1 and secondarily by adjusting VF2 and TD. Furthermore, it is activated primarily by detecting the speed change in altered feedback speech and secondarily by detecting the phonemic categorical change.

Shared perceptual processes in phoneme and word perception: Evidence from aphasia

Shared perceptual processes in phoneme and word perception: Evidence from aphasia

The effect of phonetic orthography on the perception of Mandarin syllables

It has been found that vowels have perceptual advantage over tones (e.g., Ye and Connie, 1999) and that phonetic orthographic information can be activated in speech perception (e.g., Frauenfelder, Segui, and Dijkstra, 1990). In the present study, we used a tone-vowel detection task where Zhuyin (Taiwanese) and Pinyin users (Mainland Chinese) were asked to monitor Mandarin syllables containing [i4] to test how tonal and vowel information are processed in syllable monitoring, and to examine if Zhuyin and Pinyin users’ responses are affected by their phonetic orthographic systems. The results demonstrated that in both groups, vowel-mismatched syllables (e.g., bu4) were rejected faster than tone-mismatched syllables (e.g., bi2). Moreover, the RT of rejecting vowel-mismatched syllables and double-mismatched syllables (e.g., bu2) were similar, indicating that as long as vowel was mismatched, tonal information caused little difference in RT when rejecting the mismatched syllables. This finding was consistent with Ye and Connine (1999). Furthermore, both groups resort to their phonetic orthography in simple syllables (e.g., bi4, zhi4). However, in complex syllables (e.g., biao4), different patterns were observed between the two groups, possibly due to the factors such as how tones are marked in their phonetic orthography or how they learned the orthography.

Assessment of rhythmic entrainment at multiple timescales in dyslexia: Evidence for disruption to syllable timing

Developmental dyslexia is associated with rhythmic difficulties, including impaired perception of beat patterns in music and prosodic stress patterns in speech. Spoken prosodic rhythm is cued by slow (<10 Hz) fluctuations in speech signal amplitude. Impaired neural oscillatory tracking of these slow amplitude modulation (AM) patterns is one plausible source of impaired rhythm tracking in dyslexia. Here, we characterise the temporal profile of the dyslexic rhythm deficit by examining rhythmic entrainment at multiple speech timescales. Adult dyslexic participants completed two experiments aimed at testing the perception and production of speech rhythm. In the perception task, participants tapped along to the beat of 4 metrically-regular nursery rhyme sentences. In the production task, participants produced the same 4 sentences in time to a metronome beat. Rhythmic entrainment was assessed using both traditional rhythmic indices and a novel AM-based measure, which utilised 3 dominant AM timescales in the speech signal each associated with a different phonological grain-sized unit (0.9–2.5 Hz, prosodic stress; 2.5–12 Hz, syllables; 12–40 Hz, phonemes). The AM-based measure revealed atypical rhythmic entrainment by dyslexic participants to syllable patterns in speech, in perception and production. In the perception task, both groups showed equally strong phase-locking to Syllable AM patterns, but dyslexic responses were entrained to a significantly earlier oscillatory phase angle than controls. In the production task, dyslexic utterances showed shorter syllable intervals, and differences in Syllable:Phoneme AM cross-frequency synchronisation. Our data support the view that rhythmic entrainment at slow (∼5 Hz, Syllable) rates is atypical in dyslexia, suggesting that neural mechanisms for syllable perception and production may also be atypical. These syllable timing deficits could contribute to the atypical development of phonological representations for spoken words, the central cognitive characteristic of developmental dyslexia across languages.This article is part of a Special Issue entitled <Music: A window into the hearing brain>.

Musical expertise and foreign speech perception

The aim of this experiment was to investigate the influence of musical expertise on the automatic perception of foreign syllables and harmonic sounds. Participants were Cuban students with high level of expertise in music or in visual arts and with the same level of general education and socio-economic background. We used a multi-feature Mismatch Negativity (MMN) design with sequences of either syllables in Mandarin Chinese or harmonic sounds, both comprising deviants in pitch contour, duration and Voice Onset Time (VOT) or equivalent that were either far from (Large deviants) or close to (Small deviants) the standard. For both Mandarin syllables and harmonic sounds, results were clear-cut in showing larger MMNs to pitch contour deviants in musicians than in visual artists. Results were less clear for duration and VOT deviants, possibly because of the specific characteristics of the stimuli. Results are interpreted as reflecting similar processing of pitch contour in speech and non-speech sounds. The implications of these results for understanding the influence of intense musical training from childhood to adulthood and of genetic predispositions for music on foreign language perception are discussed.

Relative contributions of spectral and temporal resolutions to the perception of syllables, words, and sentences in noise-vocoded speech

In this study, we investigated how the temporal envelopes contribute to the recognition of isolated syllables, words, and sentences in noise-vocoded speech, under comparison with the influence of spectral resolution. The spectral and temporal resolutions of speech materials were systematically manipulated by a noise-vocoding technique. Japanese monomoraic syllables, meaningful and meaningless words, and sentences were used as test speech materials. The original speech sound was spectrally separated by a filter bank, and each spectral band was replaced with band noise, preserving its original temporal envelope. Spectral resolution was controlled by varying the number of spectral bands as 4, 8, or 16 bands. Temporal resolution was altered by smoothing the amplitude envelope using a low-pass filter with cut-off frequencies at 4, 8, or 16 Hz. Results demonstrated an increased dependence on temporal resolution in comparison with spectral resolution for the recognition of speech materials at higher structural levels (i.e., monosyllables, words, and sentences). This increased temporal dependence suggests that the temporal envelope in noise-vocoded sentences contained a greater amount of suprasegmental information, such as coarticulations, prosodies, and rhythms, in the original speech sound.