Head Mapping: Search for an Optimum Bone Microphone Placement

Abstract

Bone microphones have been reported to be effective mechanisms for converting head vibrations into audio signals during speech production in high noise environments. This paper presents results of a study conducted to evaluate recordings of speech signals received by a bone microphone at various locations on the human head. Twelve different locations, four voices, and three words were used during the recording sessions. Twenty-two students evaluated 144 randomly presented recordings in a single group setting. Each recording was evaluated regarding its intelligibility (rating scale from 0 to 100%) and speech quality (rating scale 1 to 5) using a paper survey instrument. Results of the evaluation indicated significant differences in both intelligibility and quality between many of the locations and the results for intelligibility and quality were highly correlated. The two locations that resulted in the highest intelligibility and quality ratings were the forehead and temple.

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