Correction: Experience with speech sounds is not necessary for cue trading by budgerigars (Melopsittacus undulatus).

[This corrects the article DOI: 10.1371/journal.pone.

Experience with speech sounds is not necessary for cue trading by budgerigars (Melopsittacus undulatus).

The influence of experience with human speech sounds on speech perception in budgerigars, vocal mimics whose speech exposure can be tightly controlled in a laboratory setting, was measured. Budgerigars were divided into groups that differed in auditory exposure and then tested on a cue-trading identification paradigm with synthetic speech. Phonetic cue trading is a perceptual phenomenon observed when changes on one cue dimension are offset by changes in another cue dimension while still maintaining the same phonetic percept.

Perceptual normalization for speaking rate III: Effects of the rate of one voice on perception of another.

Individuals vary their speaking rate, and listeners use the speaking rate of precursor sentences to adjust for these changes (Kidd, 1989). Most of the research on this adjustment process has focused on situations in which there was only a single stream of speech over which such perceptual adjustment could occur. Yet listeners are often faced with environments in which multiple people are speaking simultaneously.

Effects of syllable-final segment duration on the identification of synthetic speech continua by birds and humans.

In an attempt to test whether experience with or knowledge of language is necessary to show typical speaking rate effects in the perception of speech, budgerigars (Melopsittacus undulatus) and humans categorized stimuli from the synthetic continua /ba/-/wa/ and /bas/-/was/, with both short and long syllable-final phonemes. This comparative approach aims to shed some light on whether knowledge of language has a role in rate normalization effects, such as using duration information as an indicator of speaking rate in human speech perception. Syllable-final phoneme durations were varied, and were either temporally adjacent to the initial target (CV series) or were nonadjacent (CVC series).

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.