Increased exposure and phonetic context help listeners recognize allophonic variants.

This study examines the influence of increased exposure and phonetic context on the recognition of words that are produced with nasal flaps in American English (e.g., the word center produced as cenner).

Listen carefully: the risk of error in spoken medication orders.

Clinicians and patients often confuse drug names that sound alike. We conducted auditory perception experiments in the United States to assess the impact of similarity, familiarity, background noise and other factors on clinicians' (physicians, family pharmacists, nurses) and laypersons' ability to identify spoken drug names. We found that accuracy increased significantly as the signal-to-noise (S/N) ratio increased, as subjective familiarity with the name increased and as the national prescribing frequency of the name increased.

Does perceptual learning in speech reflect changes in phonetic category representation or decision bias?

Recent studies show that perceptual boundaries between phonetic categories are changeable with training (Norris, McQueen, & Cutler, 2003). For example, Kraljic and Samuel (2005) exposed listeners in a lexical decision task to ambiguous /s-integral/ sounds in either s-word contexts (e.g.

Do postonset segments define a lexical neighborhood?

Previous research has demonstrated that the number and frequency of lexical neighbors affects the perception of individual sounds within a nonword in a phoneme identification task. In the present research, the issue of what items should be considered part of a word's neighborhood was explored. These experiments, in which both lexical decision and phoneme identification tasks were used, demonstrate that lexical neighborhood effects are not limited to words that match the target item syllable initially (the cohort).

Representational specificity of within-category phonetic variation in the long-term mental lexicon.

This study examines the potential encoding in long-term memory of subphonemic, within-category variation in voice onset time (VOT) and the degree to which this encoding of subtle variation is mediated by lexical competition. In 4 long-term repetition-priming experiments, magnitude of priming was examined as a function of variation in VOT in words with voiced counterparts (cape-gape) and without (cow-*gow) and words whose counterparts were high frequency (pest-best) or low frequency (pile-bile). The results showed that within-category variation was indeed encoded in memory and could have demonstrable effects on priming.

Representation of lexical form: evidence from studies of sublexical ambiguity.

The authors examined the role of intermediate, sublexical representations in spoken word perception. In particular, they tested whether flaps, which are neutralized allophones of intervocalic /t/s and /d/s, map onto their underlying phonemic counterparts. In 2 shadowing tasks, the authors found that flaps primed their carefully articulated counterparts, and vice versa.

Examining the time course of indexical specificity effects in spoken word recognition.

Variability in talker identity and speaking rate, commonly referred to as indexical variation, has demonstrable effects on the speed and accuracy of spoken word recognition. The present study examines the time course of indexical specificity effects to evaluate the hypothesis that such effects occur relatively late in the perceptual processing of spoken words. In 3 long-term repetition priming experiments, the authors examined reaction times to targets that were primed by stimuli that matched or mismatched on the indexical variable of interest (either talker identity or speaking rate).

A web-based interface to calculate phonotactic probability for words and nonwords in English.

Phonotactic probability refers to the frequency with which phonological segments and sequences of phonological segments occur in words in a given language. We describe one method of estimating phonotactic probabilities based on words in American English. These estimates of phonotactic probability have been used in a number of previous studies and are now being made available to other researchers via a Web-based interface.

Falling on sensitive ears: constraints on bilingual lexical activation.

Spoken word recognition is characterized by multiple activation of sound patterns that are consistent with the acoustic-phonetic input. Recently, an extreme form of multiple activation was observed: Bilingual listeners activated words from both languages that were consistent with the input. We explored the degree to which bilingual multiple activation may be constrained by fine-grained acoustic-phonetic information.

Representation of lexical form.

The authors attempted to determine whether surface representations of spoken words are mapped onto underlying, abstract representations. In particular, they tested the hypothesis that flaps--neutralized allophones of intervocalic /t/s and /d/s--are mapped onto their underlying phonemic counterparts. In 6 repetition priming experiments, participants responded to stimuli in 2 blocks of trials.

Speech perception and spoken word recognition: past and present.

The scientific study of the perception of spoken language has been an exciting, prolific, and productive area of research for more than 50 yr. We have learned much about infants' and adults' remarkable capacities for perceiving and understanding the sounds of their language, as evidenced by our increasingly sophisticated theories of acquisition, process, and representation. We present a selective, but we hope, representative review of the past half century of research on speech perception, paying particular attention to the historical and theoretical contexts within which this research was conducted.

Priming Lexical Neighbors of Spoken Words: Effects of Competition and Inhibition.

Two experiments employing an auditory priming paradigm were conducted to test predictions of the Neighborhood Activation Model of spoken word recognition (Luce & Pisoni, 1989, . Manuscript under review). Acoustic-phonetic similarity, neighborhood densities, and frequencies of prime and target words were manipulated.

Speech Perception, Word Recognition and the Structure of the Lexicon.

This paper reports the results of three projects concerned with auditory word recognition and the structure of the lexicon. The first project was designed to experimentally test several specific predictions derived from MACS, a simulation model of the Cohort Theory of word recognition. Using a priming paradigm, evidence was obtained for acoustic-phonetic activation in word recognition in three experiments.