Work

Exploring the Role of the Modulation Spectrum in Phoneme Recognition

Year: 2008

Type: article

Abstract: In Brief Objectives: The ability of human listeners to identify consonants (presented as nonsense syllables) on the basis of primarily temporal information was compared with the predictions of a simple model based on the amplitude modulation spectra of the stimuli calculated for six octave-spaced carrier frequencies (250 to 8000 Hz) and six octave-spaced amplitude modulation frequencies (1 to 32 Hz). Design: The listeners and the model were presented with 16 phonemes each spoken by four different talkers processed so that one, two, four, or eight bands of spectral information remained. The average modulation spectrum of each of the processed phonemes was extracted and similarity across phonemes was calculated by the use of a spectral correlation index (SCI). Results: The similarity of the modulation spectra across phonemes as assessed by the spectral correlation index was a strong predictor of the confusions made by human listeners. Conclusions: This result suggests that a sparse set of time-averaged patterns of modulation energy can capture a meaningful aspect of the information listeners use to distinguish among speech signals. The ability of listeners to identify consonants on the basis of primarily temporal information was compared with the predictions of a model based on amplitude modulation spectra. Listeners and model were presented with phonemes processed so that one to eight bands of spectral information remained. The similarity of the modulation spectra across phonemes was a strong predictor of the confusions made by human listeners, suggesting that a sparse set of time-averaged patterns of modulation energy can capture a meaningful aspect of the information listeners use to distinguish among speech signals.

Source: Ear and Hearing

DOI: 10.1097/aud.0b013e31817e73ef

Authors: Frederick Gallun, Pamela Souza

Institutions: Portland VA Medical Center, VA Portland Health Care System, University of Washington

Language: English

Topic: Phonetics and Phonology Research

Subfield: Experimental and Cognitive Psychology

Field: Psychology

Domain: Social Sciences

Open Access status: green

Funders: University College London, National Institute on Deafness and Other Communication Disorders

Awards: The ability to make multiple auditory judgments about non-speech stimuli, G3766666056, G4219695092, Acoustic and Perceptual Effects of WDRC Amplification, Core Center - NIDCD Research Core Center P30