When selective adaptation and contrast effects are distinct: A reply to Diehl, Kluender, and Parker.

Two alternative conceptualizations of selective adaptation with speech have recently received attention: the adaptation level theory (AL) outlined by R. L. Diehl (see record 1981-05067-001) and a 2-stage model outlined by the 1st author and P. Jusczyk (see record 1982-00351-001). Diehl et al (see record 1986-05428-001) reported evidence of streaming in selective adaptation and claimed that their results provide a counterdemonstration to recent studies that have argued against the AL approach. It is shown how the Diehl et al results can be accounted for by both the 2-stage model and AL theory. Results are presented from a study with 74 undergraduates that compared adaptation and paired-comparison procedures. These results are precisely as predicted by the 2-stage model, but they cannot be accounted for by AL theory. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical neighborhood effects in phonetic processing.

Previous research on spoken word recognition has demonstrated that identification of a phonetic segment is affected by the lexical status of the item in which the segment occurs. W. F. Ganong (1980) demonstrated that a category boundary shift occurs when the voiced end of 1 voice-onset time continuum is a word but the voiceless end of another series is a word; this is known as the "lexical effect." A series of studies was undertaken to examine how lexical neighborhood, in contrast to lexical status, might influence word perception. Pairs of nonword series were created in which the voiced end of 1 series had a higher frequency-weighted neighborhood density, whereas the reverse was true for the other series. Lexical neighborhood was found to affect word recognition in much the same way as lexical status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory coding, cues, and coherence in phonetic perception.

C. T. Best, M. Studdert-Kennedy, S. Manuel, and J. Rubin-Spitz (1989) reported that listeners given speech labels showed categorical-like perception of a series of complex tone analogs to a /la/-/ra/ speech series, whereas nonspeech listeners were unable to classify the stimuli consistently. In 2 experiments, a new training and testing procedure was used with adult listeners given nonspeech instructions. They classified the /la/-/ra/ tone analogs consistently, showed categorical-like perception, and generalized their training to a new, /li/-/ri/ tone analog series. Two sets of auditory attributes were described for coding the /l/-/r/ distinction, and 1 was shown to quantitatively predict listeners' classification of both series. These results are consistent with models of perception in which a rich, abstract auditory code is computed and forms the basis for both speech and nonspeech auditory categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The processing of duration and intensity cues to prominence

This paper presents results from two experiments designed to show how duration and intensity are processed during speech perception. Duration and intensity are two physical dimensions which are known to interact psychoacoustically in the perception of both length (a term that will be used for perceived duration) and loudness. The first experiment, a selective attention task, shows that length and loudness are processed as a unit [integrally, in the terms of Garner, The Processing of Information and Structure (Erlbaum, Potomac, MD, 1974)], but that the integrality is asymmetric: Extracting length information appears to be easier than extracting loudness information. The results of the first experiment make the prediction that listeners would not use loudness by itself in making prominence judgments, since the extraction of loudness in the presence of duration variation appears to require a (relatively) high processing load. The second experiment, a traditional trading relation experiment in which duration and intensity were varied orthogonally, appears to bear out this prediction. Listeners' responses were predicted from computed measures of length and loudness in a linear multiple regression analysis. Results show a negligible independent contribution of loudness to listeners' responses. Listeners' behavior is best predicted by computed measures of length.