Hands-free voice communication in an automobile with a microphone array

Abstract

In this paper, we present the results of our research on developing a hands-free voice communication system with a microphone array for use in an automobile environment. The goal of this research is to develop a speech acquisition and enhancement system so that a speech recognizer can reliably be used inside a noisy automobile environment, for the digital cellular phone application. Speech data has been collected using a microphone array and a Digital Audio Tape (DAT) recorder inside a real car for several idling and driving conditions, and processed using delay-and-sum and adaptive beamforming algorithms. Performance criteria including signal-to-noise ratio and speech recognition error rate have been evaluated for the processed data. Detailed performance results presented in this paper show that the microphone array is superior to a single microphone.

A practical methodology for speech source localization with microphone arrays

“…Existing array systems have been used in a number of applications. These include teleconferencing (Flanagan, 1985a,b;Flanagan et al, 1991;Kellerman, 1991), speech recognition (Silverman, 1987;Che, Rahim & Flanagan, 1992;Che et al, 1994;Giuliani, Omologo & Svaizer, 1994), speaker identification (Lin, Jan & Flanagan, 1994), speech acquisition in an automobile environment (Grenier, 1992;Oh, Viswanathan & Papamichalis, 1992), sound capture in reverberant enclosures (Flanagan, Surendran & Jan, 1993;Adugna, 1994;Jan, Svaizer & Flanagan, 1995), largeroom recording-conferencing (Flanagan et al, 1985), acoustic surveillance (Omologo & Svaizer, 1993, 1994, and hearing aid devices (Greenberg & Zurek, 1992). …”

Sound Source Distance Estimation in Rooms based on Statistical Properties of Binaural Signals

“…where is the distance between the sound source and receiver given in critical distance units as (3) where is the actual source/receiver distance (in m) and is the critical distance of the room, given by [24]: (4) where V is the volume of the room, is a constant equal to 0.161 and (sec) is the reverberation time of the room. Combining (1) and (2) leads to (5) Equation (5) indicates the systematic dependency of the distance between source and receiver on the RTF spectral standard deviation.…”

A practical time-delay estimator for localizing speech sources with a microphone array

“…Existing array systems have been used in a number of applications. These include teleconferencing (Flanagan, 1985;Kellerman, 1991), speech recognition (Silverman, 1987;Che, Lin, Pearson, deVries & Flanagan, 1994), speaker identification (Lin, Jan & Flanagan, 1994), speech acquisition in an automobile environment (Grenier, 1992;Oh, Viswanathan & Papamichalis, 1992), large-room recording-conferencing (Flanagan, Johnson, Zahn & Elko, 1985), and hearing aid devices (Greenberg & Zurek, 1992). These systems also have the potential to be beneficial in several other environments, e.g.…”