1 2 3 4 5 6 7 8 Perception of sinewave vowels 9 10 11

46 There is a significant body of research examining the intelligibility of sinusoidal replicas of 47 natural speech. Discussion has followed about what the sinewave speech phenomenon might 48 imply about the mechanisms underlying phonetic recognition. However, most of this work has 49 been conducted using sentence material, making it unclear what the contributions are of 50 listeners’ use of linguistic constraints versus lower level phonetic mechanisms. This study was 51 designed to measure vowel intelligibility using sinusoidal replicas of naturally spoken vowels. 52 The sinusoidal signals were modeled after 300 /hVd/ syllables spoken by men, women, and 53 children. Students enrolled in an introductory phonetics course served as listeners. Recognition 54 rates for the sinusoidal vowels averaged 55%, much lower than the ~95% intelligibility of the 55 original signals. Attempts to improve performance using three different training methods met 56 with modest success, with post-training recognition rates rising by ~5-11 percentage points. 57 Follow-up work showed that more extensive training produced further improvements, with 58 performance leveling off at ~73-74%. Finally, modeling work showed that a fairly simple 59 pattern-matching algorithm trained on naturally spoken vowels classified sinewave vowels with 60 78.3% accuracy, showing that the sinewave speech phenomenon does not necessarily rule out 61 template matching as a mechanism underlying phonetic recognition. 62 Hillenbrand, Clark, and Baer: Perception of sinewave vowels 3/21/2011 3