Auditory training with phonetic variability and acoustic enhancement: A comparison of /r/–/l/ training techniques for Japanese adults
Paul Iverson, Kerry Bannister, Valerie L. Hazan · The Journal of the Acoustical Society of America · 2004
High-variability phonetic training (HVPT) techniques have been successful for helping Japanese adults learn the English /r/–/l/ distinction. This success has been attributed to the fact that HVPT exposes listeners to naturalistic phonetic variability, from many talkers and phonetic contexts [e.g., Logan et al., J. Acoust. Soc. Am. 89, 874–886 (1991)]. The present investigation examined whether naturalistic phonetic variability is essential for effective training. HVPT (natural recordings from ten talkers) was compared with three conditions, in which signal processing was used to alter the phonetic variability of these natural recordings: all enhancement (F3 set to extreme values); perceptual fading (amount of F3 enhancement progressively decreased during training); and secondary cue variability (variability in F2 and duration cues progressively increased during training). The results thus far suggest that all of these training techniques were similarly effective, improving /r/–/l/ identification by an average of 15–20 percentage points for Japanese adults. It appears that the presence of naturalistic phonetic variability may not be critical to the effectiveness of HVPT. [Work supported by ESRC.]