Role of stop consonants in word recognition

Abstract

The perceptibility of various phonetic features during word recognition was assessed by having listeners detect systematic mispronunciations of words in a short story. Mispronunciations were produced by changing a single-consonant segment to produce a nonsense word (e.g., “boy” to “poy”). The rationale behind the experiments was that, in order to perceive a word as mispronounced, the listener must make a phonetic discrimination. Therefore, the listening for mispronunciation task examines the use of phonetic information during the process of recognizing words from fluent speech. The results of six experiments revealed that changes involving prestressed word-initial-stop consonants were detected more often than changes involving any other consonant. Thus, voicing changes were better detected in stops than in fricatives (70% versus 38%). Changes in manner of articulation were also better detected in stops than in fricatives (84% versus 53%). Changes in place of articulation in stops were better detected than place changes in nasals (77% versus 64%) and voicing changes in stops were better detected than place changes in nasals (75% versus 69%). Voicing and place changes in stops were consistently well detected (at least 70%) over three speakers differing in speech style and rate. The results showed that phonetic features are more perceptible in stops than in other consonants in fluent speech. The results suggest that stop consonants in word-initial position provide the most important and reliable phonetic information about a word's identity in fluent speech. They therefore play a special role in the word recognition process.