The Perception of Consonant Voicing and Place of Articulation in Fricatives-Vowels with Consonant Duration Modifications

The previous research suggests that a speaking style known as clear speech is more intelligible than casual conversational speech for hearing impaired listeners. The present paper is an extension of author’s previous work addressing the temporal modifications to the clear speech intelligibility advantage. The primary goal of this work is to determine whether clear speech enhances fricative intelligibility for normal-hearing listeners with simulated impairment. Two acoustic correlates of fricative consonants namely, noise duration and formant transition duration are time-expanded selectively by 50/ 100% of their original duration. The effects of consonant duration modifications on the perception of production-based features such as voicing and place of articulation were studied. The perception in noise tests are quantified in terms of information transmission analysis measures, in the presence of white noise-masker at three noise levels, 0 dB, +12 dB, and +6 dB. Results suggested that formant transition lengthening by 50% of their original duration reported significant intelligibility improvement with respect to place of articulation feature in all three vowel contexts, in consistent with previous findings. Noise duration lengthening by 50% and 100% have less perceptual significance and does not seem to carry cues to voicing and place of articulation.