Speech Perception Within an Auditory Cognitive Science Framework

Abstract

The complexities of the acoustic speech signal pose many significant challenges for listeners. Although perceiving speech begins with auditory processing, investigation of speech perception has progressed mostly independently of study of the auditory system. Nevertheless, a growing body of evidence demonstrates that cross-fertilization between the two areas of research can be productive. We briefly describe research bridging the study of general auditory processing and speech perception, showing that the latter is constrained and influenced by operating characteristics of the auditory system and that our understanding of the processes involved in speech perception is enhanced by study within a more general framework. The disconnect between the two areas of research has stunted the development of a truly interdisciplinary science, but there is an opportunity for great strides in understanding with the development of an integrated field of auditory cognitive science.Keywords speech perception; auditory perception; auditory cognitive scienceThe ease with which a listener perceives speech in his or her native language belies the complexity of the task. A spoken word exists as a fleeting fluctuation of air molecules for a mere fraction of a second, but listeners are usually able to extract the intended message. The seemingly trivial ability to determine that the spoken words dean, den, dune, and dawn begin with the same English consonant, /d/, is actually a remarkable accomplishment. There are a number of physical acoustic characteristics associated with the production of /d/, and they unfold quickly across just tens of milliseconds. These acoustic correlates vary with the following vowel (such that the initial sound in dean is distinct from that of dune) and the preceding word context, as well as with the dialect, gender, emotional state, and physical stature of the speaker. To make matters more challenging, the particular acoustic correlates utilized by a listener depend on that listener's native language and expectations. Invariant perception ("these are all /d/s") in the face of variable acoustic signals has been one of the central puzzles in the study of speech perception for more than 50 years.Presumably, understanding how the auditory system processes complex sounds can be informative about how speech perception is accomplished; and, likewise, investigation of speech perception can provide clues to how the auditory system functions. Unfortunately,

Unequal effects of speech and nonspeech contexts on the perceptual normalization of Cantonese level tones

“…Liberman et al, 1967;Liberman and Mattingly, 1985), different from nonspeech sounds. The other view proposes a general perceptual mechanism that underlies the processing of both speech and nonspeech sounds (e.g., Holt, 2006a,b;Holt and Lotto, 2008). It is yet unclear whether the processing of suprasegmental properties of speech such as lexical tones recruits the speech-specific mechanism (Francis et al, 2006), or whether the normalization of lexical tones is mediated by the general perceptual mechanism Holt, 2009, 2011).…”

Individual differences in perceptual adaptability of foreign sound categories

“…Speech perception can be thought of as an example of a general auditory categorization task, with sound categories being mapped onto a multi-dimensional acoustic space (Goudbeek et al, 2005; Holt and Lotto, 2008; Goudbeek et al, 2009; Holt and Lotto, 2010). Speech sounds contrast on many acoustic dimensions (or “cues”), and listeners give different “weights” to these dimensions.…”

Compensation for Complete Assimilation in Speech Perception: The Case of Korean Labial-to-Velar Assimilation

“…Given the assumption that the phonetic categorization occurs at the phonetic level, the failure to find the context effect with the phonetic categorization task could be interpreted as supporting the dissociation between the phonetic and the phonological filtering stages as assumed by the phonological inference account. The perceptual-integration account, on the other hand, assumes that context effects are a consequence of early and mandatory auditory processes (somewhat in line with proposals form an auditory framework for speech perception, see Holt & Lotto, 2008), and therefore predicts that the context effect should be evident in any task (see Mitterer, 2011b, for a fuller development of this argument). Finding a context effect, however, does not allow us to decide between the two accounts.…”

“…Classical examples of context effects in speech perception, such as normalization for speaking rate (Newman & Sawusch, 1996) and for phonemic contexts (Mann, 1980) are often assumed to arise early in the perceptual process (Holt & Lotto, 2008) and are linked to uncertainty about the identity of the target phoneme as has been evident in robust context effects for the most ambiguous targets. The different pattern for the current context effect may be taken as an indication that this arises at a later stage in the perceptual process, so that in fact certainty about the identity of the target phoneme is important for the context effect to arise.…”