Acoustic Position Estimation of a Silent Listener

The localization of sounding objects has been extensively studied. In certain situations, however, an object of interest may not emit sound while another sound source is active. For instance, this occurs when a silent human listens to music and needs to be localized, e.g., to optimize the playback for the listener’s position. In this study, we present a method for localizing silent listeners: By continuously estimating room impulse responses using a loudspeaker emitting a known signal and a microphone array, we can detect subtle variations in the room impulse response over time, which are induced by the listener’s motion. Our results, evaluated in two different rooms, indicate that six room impulse responses, estimated using two successive 20 Hz-24 kHz sine sweeps of 1 s duration and each captured at three spatial points, are sufficient to localize a sitting listener within 35 cm accuracy 82 % and a standing listener 93 % of the time.