Intelligibility of Hindi-Accented English: the role of duration and intonation.

Abstract

In order to examine the contribution of prosodic variables to the intelligibility of foreign-accented speech, this study asked listeners to provide intelligibility ratings of Hindi-accented English sentences that were acoustically manipulated along two parameters: duration (of segments and pauses) and F0. The manipulated sentences, which reflected typical American English patterns of duration and pitch, were presented to native American English listeners in the presence of background noise. The findings were that for Hindi-accented English, manipulating F0 has a greater effect on intelligibility than does manipulating duration. When duration and F0 were each manipulated separately, both manipulations led to reduced intelligibility. Manipulating F0 led to a greater detriment in speech intelligibility than manipulating duration. Furthermore, the lowest intelligibility performance of all resulted from sentences where both duration and F0 had been modified. Even though the prosodic variables were manipulated to be native-like and to therefore enhance intelligibility, these manipulations resulted worse performance on the part of native listeners. Possible reasons for these findings and directions for future research are discussed.