Effects Of Talker Variability Research Articles

Linking acoustic variability in the infants' input to their early word production.

Exposure to talker variability shapes how learning unfolds in the lab, and occurs in the everyday speech infants hear in daily life. Here, we asked whether aspects of talker variability in speech input are also linked to the onset of word production. We further asked whether these effects were redundant with effects of speech register (i.e.,whether speech input was adult- vs.child-directed). To do so, we first extracted a set of highly common nouns from a longitudinal corpus of home recordings from North-American English-learning infants. We then used the acoustic variability in how these tokens were said to predict when the children first produced these same nouns. We found that in addition to frequency, variability in how words sound in 6-17 month's input predicted when children first said these words. Furthermore, while the proportion of child-directed speech also predicted the month of first production, it did so alongside measurements of acoustic variability in children's real-world input. Together, these results add to a growing body of literature suggesting that variability in how words sound in the input is linked to learning both in the lab and in dailylife. RESEARCH HIGHLIGHTS: Talker variability shapes learning in the lab and exists in everyday speech; we asked whether it predicts word learning in the real world. Acoustic measurements of early words in infants' input (and their frequency) predicted when infants first said those same words. Speech register also predicted when infants said words, alongside effects of talker variability. Our results provide a deeper understanding of how sources of variability inherent to children's input connect to their learning and development.

Assessment of High-variability Speech Recognition in Adult Cochlear Implant Users using PRESTO.

Speech recognition in adult cochlear implant (CI) users is typically assessed using sentence materials with low talker variability. Little is known about the effects of talker variability on speech recognition in adult CI users, the factors underlying individual differences in speech recognition with high talker variability, or how sentence materials with high talker variability could be utilized clinically. To examine the effects of talker variability on sentence recognition in adult CI users, using sentences from the Perceptually Robust English Sentence Test Open-Set (PRESTO), and to examine the relation between working memory capacity and high-variability speech recognition. Postlingually deafened adult CI users and normal-hearing (NH) listeners under CI simulation completed sentence recognition tests that contained varying levels of talker variability, including HINT (low-variability), AzBio (moderate-variability), and PRESTO sentences (high-variability). The tasks were completed in both quiet and multi-talker babble (MTB). For the adult CI users only, the relation between sentence recognition accuracy and working memory capacity was assessed. Twenty postlingually deafened adult CI users and 35 NH adults under 8-channel acoustic noise-vocoder simulations of CI hearing. In both CI and NH groups, performance decreased as a function of increased talker variability, with the best scores obtained on HINT (low-variability), then AzBio (moderate-variability), followed by PRESTO (high-variability) in quiet. In MTB, performance was significantly lower on PRESTO sentences, compared to HINT and AzBio sentences, which were not significantly different. Working memory capacity in the CI users was related to sentence recognition accuracy across all materials and conditions. Findings from the current study suggest that the increased talker variability in the PRESTO sentence materials has a detrimental effect on speech recognition in both adult CI users and NH listeners under CI simulation, particularly when speech is further degraded by MTB. For adult CI users, working memory capacity contributes to speech recognition abilities. Sentence recognition testing with high-variability, multi-talker materials, as in PRESTO, provides robust assessment of speech recognition abilities for research and clinical application, generating a wide range of scores for evaluating individual differences without ceiling effects when compared to conventional low-variability sentences.

Talker variability in Mandarin spoken word recognition: Comparing normal and hearing-impaired listeners

During natural speech processing, talker variability is inherently embedded in the acoustic signal and may affect the speed and accuracy of processing. Prior studies have demonstrated the effect of talker variability in normal listeners. What is the effect of inter-talker variability in people with hearing impairment? This study aims to explore the question in native speakers of Mandarin Chinese, trying to compare listeners with and without hearing impairment. Participants are instructed to listen to pre-recorded pairs of Mandarin Chinese words (e.g., in English translation, happy – sad) and make responses only to the second item of each pair (e.g., sad) in a short-term priming paradigm. The speed and accuracy of the responses are measured. The fact that the pairs were spoken by either the same or different native speakers of Mandarin Chinese allows us to examine the effect of speaker voice change on the reaction time and accuracy. The hearing-impaired listeners appear to be facilitated more by the same speaker voice condition in terms of response accuracy, compared with the listeners without hearing impairment. There also seems to be more semantic facilitation to the hearing-impaired in terms of reaction time, although this effect does not seem to be modulated by talker variability.

Brain aging and speech perception: Effects of background noise and talker variability

Speech perception can be challenging, especially for older adults. Despite the importance of speech perception in social interactions, the mechanisms underlying these difficulties remain unclear and treatment options are scarce. While several studies have suggested that decline within cortical auditory regions may be a hallmark of these difficulties, a growing number of studies have reported decline in regions beyond the auditory processing network, including regions involved in speech processing and executive control, suggesting a potentially diffuse underlying neural disruption, though no consensus exists regarding underlying dysfunctions. To address this issue, we conducted two experiments in which we investigated age differences in speech perception when background noise and talker variability are manipulated, two factors known to be detrimental to speech perception. In Experiment 1, we examined the relationship between speech perception, hearing and auditory attention in 88 healthy participants aged 19 to 87 years. In Experiment 2, we examined cortical thickness and BOLD signal using magnetic resonance imaging (MRI) and related these measures to speech perception performance using a simple mediation approach in 32 participants from Experiment 1. Our results show that, even after accounting for hearing thresholds and two measures of auditory attention, speech perception significantly declined with age. Age-related decline in speech perception in noise was associated with thinner cortex in auditory and speech processing regions (including the superior temporal cortex, ventral premotor cortex and inferior frontal gyrus) as well as in regions involved in executive control (including the dorsal anterior insula, the anterior cingulate cortex and medial frontal cortex). Further, our results show that speech perception performance was associated with reduced brain response in the right superior temporal cortex in older compared to younger adults, and to an increase in response to noise in older adults in the left anterior temporal cortex. Talker variability was not associated with different activation patterns in older compared to younger adults. Together, these results support the notion of a diffuse rather than a focal dysfunction underlying speech perception in noise difficulties in older adults.

EFFECTS OF MULTITALKER INPUT AND INSTRUCTIONAL METHOD ON THE DIMENSION-BASED STATISTICAL LEARNING OF SYLLABLE-TONE COMBINATIONS

AbstractTo test the effects of talker variability and explicit instruction on the statistical learning of lexical tone, 80 monolingual English listeners were taught an artificial language that mimicked Mandarin’s asymmetric distribution of syllable-tone co-occurrences. Training stimuli consisted of either speech from one talker or speech from four talkers. Participants were either never instructed or explicitly taught associations between phonemes (CVs), tones, and nonce symbols across four consecutive days. Learning was assessed by the accuracy of mouse clicks and eye movements to visual nonce symbols. Critical trials induced competition between the target symbol, which matched the acoustic input, and a competitor symbol that had a statistically more probable tone (but mismatched the acoustic input). Eye fixations indicated that participants were sensitive to syllable-tone co-occurrence probabilities even without explicit instruction of tone. The degree to which statistical knowledge was used to recognize words appeared to increase when participants processed more variable speech.

Tone differentiation as a means for assessing non-native imitation of Thai tones by Mandarin speakers

Non-native tone production and imitation have been found to be phonetically deviant from native production for some discrete measures. However, it remains unresolved whether non-native imitation differs from native production in terms of the differentiation of tones in acoustic tone space. 32 native Mandarin speakers who had no experience with Thai imitated five Thai tones, and each participant produced 160 tokens in total under differing memory load and stimulus variability conditions to determine effects of cognitive demands. We calculated two tone differentiation indices (i.e., Index 1: tone differentiation within the tonal space; Index 2: differentiation among tones, both as in Barry & Blamey, 2004) based on F0 onset and F0 offset for Thai tones and the non-native imitations of these Thai tones by Mandarin imitators. There was a significant memory load by vowel variability interaction for Index 1 and a main effect of talker variability and a three-way interaction (memory load “talker variability” vowel variability) for Index 2, suggesting that tone differentiation is affected by cognitive factors. Nonetheless, non-native tone imitations were not significantly different from native productions on either index, indicating that non-native imitation resembles native production in terms of tone differentiation in an onset-offset F0 space.

The role of talker variability in the perceptual learning of Mandarin tones by American English listeners

Abstract Research on segmentals has suggested that a key component of High Variability Phonetic Training (HVPT) is high talker variability. However, the extent to which high talker variability improves perception of tones is unclear. This study examined the effects of high talker variability on the perception of Mandarin tones (Tones 1–4) by English-speaking listeners. A training paradigm that used multiple talkers (multitalker group) was compared with a paradigm that used one talker (single-talker group). The results showed that the multitalker group outperformed the single-talker group, and they retained their learning better than the single-talker group did for 6 months. Neither group, however, improved their perception of Tone 1 or generalized their learning of monosyllables to disyllables. The results suggest that although high talker variability can effectively improve tone perception, it does not improve the perception of more tone categories or yield generalization of learning to more contexts compared to low talker variability.

Effects of talker variability on spoken word recognition for adult cochlear implant users

Cochlear implants (CIs) have been highly successful in providing a restored sense of hearing to profoundly deaf individuals. However, CI users must rely on a signal that is highly degraded in acoustic-phonetic details, conveying limited talker information. Normal-hearing (NH) listeners devote processing resources to accommodating talkers’ voices, and show less accurate and slower word recognition in multiple-talker compared to single-talker conditions. CI users may display a different strategy in adapting to new talkers due to limitations in talker discrimination. The current study examined the effects of talker variability on spoken word recognition by experienced, post-lingually deafened adult CI users, and the extent to which talker variability effects are mediated by limitations in talker discrimination. Word recognition accuracy for lexically easy and hard words were obtained in single-talker and multiple-talker conditions, varying by gender (female, male, mixed). Results demonstrated that single-talker performance was highly variable, but a detrimental effect of talker variability was observed in mixed conditions, when talker differences were best discriminated, particularly for hard lexical items. Taken together, findings suggest that while CI users may be affected less by talker variability overall, they may display a similar strategy as NH listeners for talker adaptation when talker differences are discriminable.

The effects of high versus low talker variability and individual aptitude on phonetic training of Mandarin lexical tones.

High variability (HV) training has been found to be more effective than low variability (LV) training when learning various non-native phonetic contrasts. However, little research has considered whether this applies to the learning of tone contrasts. The only two relevant studies suggested that the effect of HV training depends on the perceptual aptitude of participants (Perrachione et al., 2011; Sadakata & McQueen, 2014). The present study extends these findings by examining the interaction between individual aptitude and input variability using natural, meaningful second language input (both previous studies used pseudowords). A total of 60 English speakers took part in an eight session phonetic training paradigm. They were assigned to high/low/high-blocked variability training groups and learned real Mandarin tones and words. Individual aptitude was measured following previous work. Learning was measured using one discrimination task, one identification task and two production tasks. All tasks assessed generalization. All groups improved in both the production and perception of tones which transferred to untrained voices and items, demonstrating the effectiveness of training despite the increased complexity compared with previous research. Although the LV group exhibited an advantage with the training stimuli, there was no evidence for a benefit of high-variability in any of the tests of generalisation. Moreover, although aptitude significantly predicted performance in discrimination, identification and training tasks, no interaction between individual aptitude and variability was revealed. Additional Bayes Factor analyses indicated substantial evidence for the null for the hypotheses of a benefit of high-variability in generalisation, however the evidence regarding the interaction was ambiguous. We discuss these results in light of previous findings.

The effect of talker variability on word recognition under cochlear implant simulation

Normal-hearing (NH) listeners have been shown to be less accurate and/or slower to recognize spoken words when the talker changes from trial to trial, compared to when the talker remains the same. Less is known about the effect of talker variability on cochlear implant (CI) users, who display a limitation in talker perception. As a first step, the current study investigated how limited talker information via CI simulation influences word recognition. In two experiments, NH listeners completed a word naming task in different talker conditions (single (ST), multiple female (MT-F), and multiple female/male (MT-M)) and simulation conditions (12, 8, and 4 vocoder channels). An effect of talker variability was observed, but only when talker differences were maximized. Listeners were less accurate, but not slower, at recognizing words under the MT-M condition, compared to ST and MT-F conditions. Talker variability effects did not vary by the simulation condition. These results are consistent with previous studies with NH listeners, showing similar performance in conditions where talker changes were not detected but talker differences were large. Taken together, these findings suggest that limitations in talker perception for NH listeners under CI simulation, and potentially CI users, alters the perceptual strategy for recognizing words under multiple-talker conditions.Normal-hearing (NH) listeners have been shown to be less accurate and/or slower to recognize spoken words when the talker changes from trial to trial, compared to when the talker remains the same. Less is known about the effect of talker variability on cochlear implant (CI) users, who display a limitation in talker perception. As a first step, the current study investigated how limited talker information via CI simulation influences word recognition. In two experiments, NH listeners completed a word naming task in different talker conditions (single (ST), multiple female (MT-F), and multiple female/male (MT-M)) and simulation conditions (12, 8, and 4 vocoder channels). An effect of talker variability was observed, but only when talker differences were maximized. Listeners were less accurate, but not slower, at recognizing words under the MT-M condition, compared to ST and MT-F conditions. Talker variability effects did not vary by the simulation condition. These results are consistent with previous studie...

Effects of talker variability on categorization of spectrally degraded vowels

When spectral properties differ between earlier (context) and later (target) sounds, categorization of later sounds becomes biased through spectral contrast effects (SCEs). Recent work has shown that talker variability diminishes SCEs: shifts in vowel categorization were smaller when context sentences were spoken by 200 talkers than one talker [Assgari and Stilp, JASA (2015)]. CI users’ speech categorization is also influenced by SCEs [Feng and Oxenham, JASA (2018)] but are known to struggle with talker discrimination. Here, we tested whether talker variability affected context effects in spectrally degraded speech perception. Listeners categorized target vowels varying from “ih” as in “bit” to “eh” as in “bet” following 200 context sentences spoken by one or 200 talkers (from Assgari and Stilp, 2015). Sentences had 5-dB spectral peaks added to low-F1 (100–400 Hz) or high-F1 (550–850 Hz) frequencies (to produce SCEs) then were noise vocoded at different spectral resolutions. At 4 and 8 channels, the experiment was too difficult to produce reliable results (flat categorization functions). At 12 and 24 channels, SCEs occurred but did not significantly differ across one-talker and 200-talker conditions. Talker variability does not appear to affect perception of spectrally degraded speech in the same way it does for normal-hearing listeners.

Effects of type, token, and talker variability in speech processing efficiency

Phonetic variability across talkers imposes additional processing costs during speech perception, evident in performance decrements for mixed- versus single-talker speech. However, within-talker phonetic variation across different utterances is another, relatively unexplored source of variability in speech, and it is unknown how processing costs from within-talker variation compare to those from between-talker variation. Cognitive consequences of talker variability are also mostly measured from two-alternative forced-choice tasks, whereas naturalistic speech processing occurs in a much larger decision space. Do talker-variability effects scale when both the stimuli and the decision space are more complicated? Here, we measured response times in a speeded word identification task that factorially manipulated three dimensions of speech variability: number of talkers (one versus four), number of target word choices (two versus six), and number of talker-specific exemplars per word (one versus eight). Across all eight experimental levels, larger decision spaces led to significantly slower word identification. Word identification was also slower in conditions with mixed talkers and conditions with multiple exemplars. This pattern of interactions suggests complex processing relationships between type, token, and talker variability and provides preliminary evidence for how both within- and between-talker variability impose additional processing costs in speech perception.

Effects of talker continuity and speech rate on auditory working memory.

Speech processing is slower and less accurate when listeners encounter speech from multiple talkers compared to one continuous talker. However, interference from multiple talkers has been investigated only using immediate speech recognition or long-term memory recognition tasks. These tasks reveal opposite effects of speech processing time on speech recognition - while fast processing of multi-talker speech impedes immediate recognition, it also results in more abstract and less talker-specific long-term memories for speech. Here, we investigated whether and how processing multi-talker speech disrupts working memory maintenance, an intermediate stage between perceptual recognition and long-term memory. In a digit sequence recall task, listeners encoded seven-digit sequences and recalled them after a 5-s delay. Sequences were spoken by either a single talker or multiple talkers at one of three presentation rates (0-, 200-, and 500-ms inter-digit intervals). Listeners' recall was slower and less accurate for sequences spoken by multiple talkers than a single talker. Especially for the fastest presentation rate, listeners were less efficient when recalling sequences spoken by multiple talkers. Our results reveal that talker-specificity effects for speech working memory are most prominent when listeners must rapidly encode speech. These results suggest that, like immediate speech recognition, working memory for speech is susceptible to interference from variability across talkers. While many studies ascribe effects of talker variability to the need to calibrate perception to talker-specific acoustics, these results are also consistent with the idea that a sudden change of talkers disrupts attentional focus, interfering with efficient working-memory processing.

Talker normalization in typical Cantonese-speaking listeners and congenital amusics: Evidence from event-related potentials.

Despite the lack of invariance in the mapping between the acoustic signal and phonological representation, typical listeners are capable of using information of a talker's vocal characteristics to recognize phonemes, a process known as “talker normalization”. The current study investigated the time course of talker normalization in typical listeners and individuals with congenital amusia, a neurodevelopmental disorder of refined pitch processing. We examined the event-related potentials (ERPs) underling lexical tone processing in 24 Cantonese-speaking amusics and 24 typical listeners (controls) in two conditions: blocked-talker and mixed-talker conditions. The results demonstrated that for typical listeners, effects of talker variability can be observed as early as in the N1 time-window (100–150 ms), with the N1 amplitude reduced in the mixed-talker condition. Significant effects were also found in later components: the N2b/c peaked significantly earlier and the P3a and P3b amplitude was enhanced in the blocked-talker condition relative to the mixed-talker condition, especially for the tone pair that is more difficult to discriminate. These results suggest that the blocked-talker mode of stimulus presentation probably facilitates auditory processing and requires less attentional effort with easier speech categorization than the mixed-talker condition, providing neural evidence for the “active control theory”. On the other hand, amusics exhibited comparable N1 amplitude to controls in both conditions, but deviated from controls in later components. They demonstrated overall later N2b/c peak latency significantly reduced P3a amplitude in the blocked-talker condition and reduced P3b amplitude irrespective of talker conditions. These results suggest that the amusic brain was intact in the auditory processing of talker normalization processes, as reflected by the comparable N1 amplitude, but exhibited reduced automatic attentional switch to tone changes in the blocked-talker condition, as captured by the reduced P3a amplitude, which presumably underlies a previously reported perceptual “anchoring” deficit in amusics. Altogether, these findings revealed the time course of talker normalization processes in typical listeners and extended the finding that conscious pitch processing is impaired in the amusic brain.

Effect of talker variability on hearing aid benefit with closed word recognition test

The relationship between hearing aid benefit measured in a clinical setting and hearing aid performance in daily listening situations is not clearly established. A significant aspect of realistic listening situations is the variety of talkers that people normally encounter. This is a daily listening obstacle that is not easily recreated in a clinical setting; however, with the appropriate speech testing material the results could contribute to a better understanding of the benefit of amplification in realistic listening situations. Our present study investigated the interaction between talker variability and amplification benefit. Nine experienced hearing aid wearers with moderate to severe hearing loss were tested in aided and unaided conditions with the original and a multi-talker version of the WAKO word recognition test. Word recognition scores and response times were simultaneously measured for each test condition and test version. Variability of the test material was quantified in terms of the fundamental frequency and duration of each test word. The statistical analysis used a logistic mixed effect regression model on the word recognition scores and a linear mixed effect regression model on the response times. Introducing talker variability in the test material led to a significant decrease in amplification benefit for word recognition accuracy. These results suggest that using speech materials closer to that experienced in daily life might change the magnitude of measured benefit from hearing aids amplification.

Intonation and talker variability in the discrimination of Spanish lexical stress contrasts by Spanish, German and French listeners.

The perception of stress is highly influenced by listeners' native language. In this research, the authors examined the effect of intonation and talker variability (here: phonetic variability) in the discrimination of Spanish lexical stress contrasts by native Spanish (N = 17), German (N = 21), and French (N = 27) listeners. Participants listened to 216 trials containing three Spanish disyllabic words, where one word carried a different lexical stress to the others. The listeners' task was to identify the deviant word in each trial (Odd-One-Out task). The words in the trials were produced by either the same talker or by two different talkers, and carried the same or varying intonation patterns. The German listeners' performance was lower compared to the Spanish listeners but higher than that of the French listeners. French listeners performed above chance level with and without talker variability, and performed at chance level when intonation variability was introduced. Results are discussed in the context of the stress "deafness" hypothesis.

The Distribution of Talker Variability Impacts Infants' Word Learning.

Infants struggle to apply earlier-demonstrated sound-discrimination abilities to later word learning, attending to non-constrastive acoustic dimensions (e.g., Hay et al., 2015), and not always to contrastive dimensions (e.g., Stager & Werker, 1997). One hint about the nature of infants' difficulties comes from the observation that input from multiple talkers can improve word learning (Rost & McMurray, 2009). This may be because, when a single talker says both of the to-be-learned words, consistent talker's-voice characteristics make the acoustics of the two words more overlapping (Apfelbaum & McMurray, 2011). Here, we test that notion. We taught 14-month-old infants two similar-sounding words in the Switch habituation paradigm. The same amount of overall talker variability was present as in prior multiple-talker experiments, but male and female talkers said different words, creating a gender-word correlation. Under an acoustic-similarity account, correlated talker gender should help to separate words acoustically and facilitate learning. Instead, we found that correlated talker gender impaired learning of word-object pairings compared with uncorrelated talker gender-even when gender-word pairings were always maintained in test-casting doubt on one account of the beneficial effects of talker variability. We discuss several alternate potential explanations for this effect.

Talker variability effects on vocal emotion recognition in acoustic and simulated electric hearing.

Vocal emotion production varies across talkers. Effects of talker variability (i.e., same talker vs different talkers across trials) on vocal emotion recognition were tested in babble noise and with cochlear implant (CI) simulations in normal-hearing listeners. Results showed significant talker variability effects in noise but not with CI simulations, suggesting that the degree of talker variability effects on vocal emotion recognition may vary with listeners' weighting of acoustic cues for emotions (e.g., pitch and duration) and the availability of these cues in different listening conditions. Vocal emotion recognition significantly improved with higher signal-to-noise ratio and more vocoder channels.

Mandarin Tone and Vowel Recognition in Cochlear Implant Users: Effects of Talker Variability and Bimodal Hearing.

For cochlear implant (CI) users with residual low-frequency acoustic hearing in the nonimplanted ear, bimodal hearing combining the use of a CI and a contralateral hearing aid (HA) may provide more salient talker voice cues than CI alone to handle the variability of talker identity across trials. This study tested the effects of talker variability, bimodal hearing, and their interaction on response accuracy and time of CI users' Mandarin tone, vowel, and syllable recognition (i.e., combined Mandarin tone and vowel recognition in this study). Fifteen prelingually deafened native Mandarin-speaking CI users (at age 20 or lower) participated in this study. Four talkers each produced six Mandarin single-vowel syllables in four lexical tones. The stimuli were presented in quiet via a single loudspeaker. To study the effects of talker variability, Mandarin tone, vowel, and syllable recognition was tested in two presentation conditions: with stimuli blocked according to talker (blocked-talker condition) or mixed across talkers from trial to trial (mixed-talker condition). To explore the effects of bimodal hearing, two processor conditions were tested: CI alone or CI + HA. The cumulative response time was recorded as an indirect indicator of the cognitive load or listening effort in each condition. The correlations were computed between demographic/hearing factors (e.g., hearing thresholds in the nonimplanted ear) and bimodal performance/benefits (where bimodal benefits refer to the performance differences between CI alone and CI + HA). Mandarin tone recognition with both CI alone and CI + HA was significantly poorer in the mixed-talker condition than in the blocked-talker condition, while vowel recognition was comparable in the two presentation conditions. Bimodal hearing significantly improved Mandarin tone recognition but not vowel recognition. Mandarin syllable recognition was significantly affected by both talker variability and bimodal hearing. The cumulative response time significantly reduced with CI + HA compared with CI alone, but remained invariant with respect to talker variability. There was no interaction between talker variability and bimodal hearing for any performance measure adopted in this study. Correlation analyses revealed that the bimodal performance and benefits in Mandarin tone, vowel, and syllable recognition could not be predicted by the hearing thresholds in the nonimplanted ear or by the demographic factors of the participants. Talker variability from trial to trial significantly degraded Mandarin tone and syllable recognition performance in both the CI alone and CI + HA conditions. While bimodal hearing did not reduce the talker variability effects on Mandarin tone and syllable recognition, generally better Mandarin tone and syllable recognition performance with shorter response time (an indicator of less listening effort) was observed when a contralateral HA was used in conjunction with the CI. On the other hand, vowel recognition was not significantly affected by either talker variability or bimodal hearing, because ceiling effects could not be counted out of the vowel recognition results.

Effects of voice-onset time and talker variability on lexical access

The effects of voice-onset time (VOT) and talker variability on accessing word meanings were investigated. Two short-term semantic priming experiments were used to evaluate if the magnitude of semantic priming would be reduced by these two types of variability. In experiment 1, a lexical decision task and a phoneme identification task were used to examine whether listeners’ sensitivity to VOT affects their processing of a semantically related word. In experiment 2, a lexical decision task and a talker discrimination task were used to examine whether listeners’ sensitivity to talker changes affects lexical access. The results showed that while listeners were sensitive to VOT and talker variability, neither affected the magnitude of semantic priming. Nonetheless, experiment 2 also showed that talker discrimination was easier when real word targets were presented, indicating that the word/non-word lexical status affected the processing of talker information. These findings, overall, suggest that there is no ...