Personal audio reproduction using two wearable end-fire loudspeaker arrays

Abstract

We propose a wearable personal audio reproduction system that uses two end-fire loudspeaker arrays. The two loudspeaker arrays are attached in front of the listener’s breast. Consequently, the system is not close to the ears. Further, because the main beams of the two arrays are directed at each ear, crosstalk between the left and right signals is low. In addition, sound leakage is also low as a result of directivity control. We constructed a prototype of the system using four loudspeaker elements for each array, with intervals of 4 cm and array length 12 cm. The attenuation level of the area at approximately 50 cm away from the end-fire arrays was found to be -20 dB sound pressure level (SPL) relative to the main beam pointed at the ear. In addition, the crosstalk SPL difference was approximately 12 dB. We can control the sound image position by convolving the head-related transfer function with the sound source. Further, no crosstalk canceller is needed because the proposed method secures the interaural intensity difference. Improvement or application of the proposed system can facilitate realization of a personal sound field.