However, the beneficial effect of connected speech in the mixed talker condition was significantly attenuated under both anodal and cathodal stimulation versus sham. Speech is related to human physiological capability. Quarterly journal of experimental psychology,49a, 295 314. Results revealed that children do show improved spoken language processing when they are familiar with the talkers, but this improvement was limited to highly familiar lexical items. Processing cost of talker variability by speech context and stimulation condition. The results suggest that listeners encode and use acousticphonetic variability in speech to reliably perceive the dialect of unfamiliar talkers. Evidence from online processing of spoken words sarah c. The effects of talker variability on the acquisition of nonnative speech contrasts james s. Talkerspecific learning in speech perception springerlink. While talker normalization accounts have suggested that slowing due to talker variability is a consequence of using talker vocal characteristics to calibrate phoneme processing in the context of new talker, it has also been suggested that listeners also need to identify talkers for more than just reducing phonetic uncertainty. It remains unclear to what extent listeners are affected by the degree of variability within a talker, rather than simply the.
The results from a series of experiments using perceptual identification a. Yamada atr human information processing laboratories, 22 hikaridai, seika, soraku. Pdf the effect of talker variability on word recognition in. The purpose was to compare and contrast three sources of stimulus variability talker, speaking rate, and overall amplitudeto determine the extent to which each source of variability is retained in episodic memory. The effects of perceptual learning of talker identity on the recognition of spoken words and sentences were investigated in three experiments. Preschoolers easily learned distinct talkers, and a few preschoolers encoded similarsounding voices readily. Talker information is not normalized in fluent speech. Results revealed that changes in talker from trial to trial decreased speechreading performance. Recent studies suggest that speech perception is a talkercontingent process that exploits the close coupling observed between the indexical and linguistic attributes of speech. Mean interference effects of talker variability for isolated words iw and connected speech cs in each stimulation condition. The acoustic cues to consonants and vowels vary as a function of phonetic. A serial recall task was used to study the effects of changes in speaking rate, talker variability, and overall amplitude on the initial encoding, rehearsal, and recall of lists of spoken words. In addition, the effects of talker variability on word recognition appeared to be more. Effects of type, token, and talker variability in speech.
Adults encoded similar talkers easily and better than preschoolers. In a series of experiments, the authors investigated the effects of talker variability on childrens word recognition. To discover some physiological characteristics of the talker. The editors take on the difficult task of converting the mapping of speech patterns into mental representations. Stimulus variability and perceptual learning of nonnative. Accounting for phonetic variability across talkers is a core challenge in speech perception. In each experiment, listeners were trained to learn a set of 10 talkers voices and were then given an intelligibility test to assess the influence of learning the voices on the processing of the linguistic content of speech. The goal of the current study was to test whether this phenomenon is modulated by a childs language ability. Improved talker voice processing by the bilingual children suggests that a bilingual advantage exists in a social aspect of speech perception, where the focus is not on processing the linguistic information in the signal, but instead on processing.
Other research in singletalker contexts have shown, however, that when listeners are able to see a talkers face, speech recognition is. Differences in talker recognition by preschoolers and. How talker identity relates to language processing. Request pdf the perceptual consequences of within talker variability in fricative production the effect of talker and token variability on speech perception has engendered a great deal of. Preschoolers and adults learned to map voices to characters. High variability phonetic training as a bridge from. If, on the other hand, word representations are viewed as having abstracted away from direct experiences, either by represent. Processing dependencies in speech perception between voice and phoneme were investigated using the garner 1974 speeded classification procedure. Speaker normalization in speech perception uc berkeley linguistics. Variability in the voice of the talker and in the cues to wordinitial consonants were manipulated.
In order to investigate the nature of the capacity demands involved in the recall of singletalker and multipletalker word lists, a second experiment was conducted. The effect of talker variability on word recognition in. The perceptual consequences of withintalker variability. Within the first few years of life, children acquire many of the building blocks of their native language. The presence of talker variability has been evidenced by previous research to have impact on speech perception performance, and therefore, speech processing. In order to gain insight into the combined effects of some of the talker, item, and listenerrelated factors that affect speech perception, we examined spoken word recognition in two special populations using wordlength stimulus materials that were well controlled in terms of their inherent lexical difficulty. Talker variability refers to speaker differences in delivering the same linguistic information. Speech processing was faster for single talkers than mixed talkers, and connected speech reduced the additional processing costs associated with mixed talker speech. Interstimulus interval isi was manipulated to determine the time course and nature of processing. On the nature of talker variability effects on recall of. If you see a used one for sale definitely snap it up. These results suggest that talker variability in the training procedure may enhance neural efficiency in these brain areas and strengthen the cooperation between them. Children were familiarized with the voices of three germanenglish bilingual talkers and were tested on the speech of six bilinguals, three of whom were familiar.
Evidence suggests that word recognition depends on numerous talker, listener, and stimulusrelated characteristics. Speech perception and processing effect of talker variability on speech perception by elderly people in reverberation nao. Decisions about lipread speech expression and identity. A litany of studies on talker normalization have demonstrated that hearing multiple. Pdf talker variability in audiovisual speech perception.
So far, this talker variability cost has been demonstrated only in audioonly speech. It is unknown how processing costs from within talker variation compare to those from between talker variation, and how these different effects scale and interact 5, 10. Phonetic variability in speech perception and the phonological deficit in dyslexia. The general orientation of this research regards the inherent variability in the speech signal due to different talker and other instancespecific. The effects of talker voice and accent on young childrens speech perception.
Language ability and the familiar talker advantage. The current study examined the effects of talker variability and lexical difficulty on spokenword recognition among four groups of listeners. Cognitive models of word recognition address variability by employing either episodic or talkernormalization. A more comprehensive treatment will appear in the forthcoming book, theory and application of digital speech processing 101. Talker familiarity and spoken word recognition in school. Effects of talker variability on speechreading springerlink. Talker variability in audiovisual speech perception. Talker variability in speech processing book, 1997. They cover theories of perception and cognition, issues in clinical speech pathology, and the practical concerns of speech technology. To analyze speech for automatic recognition and extraction of information. Varying acousticphonemic ambiguity reveals that talker. Purpose previous studies with children and adults have demonstrated a familiar talker advantagebetter word recognition for familiar talkers. Noninvasive neurostimulation of left temporal lobe.
Highlights talker variability pervades the speech signal, but we know little about how its processing changes over development. In contrast, lexical discriminability a signalindependent factor exerted a. Effects of talker variability on recall of spoken word lists. Taller bars reflect greater differences in word identification response time between the mixed vs. This is a volume of papers that i edited with john mullennix. The speech signal is characterized by extreme variability in its acoustic composition. The point of the book is that when you consider the range of. One of the persistent puzzles in understanding human speech perception is how listeners cope with talker variability. Rather than brushing talker differences aside, explicit examination of the role of talker variability and talker identity in language processing can illuminate our understanding of the origins of. Some effects of talker variability on spoken word recognition. Talker variability in speech processing by johnson, keith, 1958. Keywords dialect categorization, indexical properties, perceptual learning, speech perception, talker variability. Compensation for contextual variability during acoustic cue encoding and categorization by joseph christopher toscano a thesis submitted in partial fulvllment of the requirements for the doctor of philosophy degree in psychology in the graduate college of the university of iowa july 2011. The effect of talker and token variability on speech perception has engendered a great deal of research.
Specifically, we found that the effect of talker variability across items in a list a signaldependent factor was equivalent across native and nonnative listeners, and across younger and older listeners. Instead, here we are interested in how and when listeners must incur processing costs to solve the challenge of talker variability during speech. Goldinger on the nature of perceptual adjustments to voice john w. One thing that might help listeners is structure in talker variability. Talker variability in speech processing guide books. Our findings highlight the brain processing of newly learned speech patterns is. Lexical and talker effects on word recognition among.
Stimulus variability and processing dependencies in speech perception. Impact of talker adaptation on speech processing and. Nevertheless, several studies have shown that speech perception and spoken word recognition are affected by talker variability. This study investigated the encoding of the surface form of spoken words using a continuous recognition memory task. Effects of talker, rate, and amplitude variation on. The effects of talker variability on visual speech perception were tested by having subjects speechread sentences from either single talker or mixed talker sentence lists. The results also replicate past findings that talker variability increases cognitive load e. However, most of this research has compared listener performance in multiple talker or variable situations to performance in single talker conditions. Effects of talker variability on perceptual learning of. Pdf talker normalization is mediated by structured.
Unique in its approach, talker variability in speech processing embraces the differences in speech patterns without treating them as unwanted variables. Effect of talker variability on speech perception by. It is unknown how processing costs from withintalker variation compare to those from betweentalker variation, and how these different effects scale and interact 5, 10. Perception of speech produced by native and nonnative. Pdf speech perception is challenged by indexical variability. In particular, variability in talker has been shown to benefit the longterm memory representations of speech that can facilitate recognition when. Stimulus variability and processing dependencies in speech. Differences in talker recognition by preschoolers and adults. Pdf phonetic variability in speech perception and the. Digital speech processing lecture 1 introduction to digital speech processing 2 speech processing speech is the most natural form of humanhuman communications. Talker and acoustic variability in learning to produce nonnative sounds.
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