Bone conduction equal loudness contours at different placements, conditions, and intensities

Abstract

Bone conduction transmission has been studied for decades; however, equal loudness contours for bone conduction have not been established. The purpose of the current study was to establish bone conduction equal loudness contours at two different placements (mastoid and condyle), in two different conditions (unilateral and bilateral) and at two different intensities (20 and 40 dB HL). The study included three parts, soundfield equal loudness contours, soundfield to bone conduction loudness comparisons and bone conduction equal loudness contours. Results showed that there was no difference between any of the conditions or placements for bone conduction equal loudness contours. Also, the bone conduction equal loudness values closely matched the published ISO values established with a 1000 Hz reference at 20 and 40 dB HL.