Using Reverberation to Improve Range and Elevation Discrimination for Small Array Sound Source Localization

Sound source localization (SSL) is an essential task in

many applications involving speech capture and enhancement. As

such, speaker localization with microphone arrays has received

significant research attention. Nevertheless, existing SSL algorithms

for small arrays still have two significant limitations: lack

of range resolution, and accuracy degradation with increasing

reverberation. The latter is natural and expected, given that strong

reflections can have amplitudes similar to that of the direct signal,

but different directions of arrival. Therefore, correctly modeling

the room and compensating for the reflections should reduce

the degradation due to reverberation. In this paper, we show

a stronger result. If modeled correctly, early reflections can be

used to provide more information about the source location than

would have been available in an anechoic scenario. The modeling

not only compensates for the reverberation, but also significantly

increases resolution for range and elevation. Thus, we show that

under certain conditions and limitations, reverberation can be

used to improve SSL performance. Prior attempts to compensate

for reverberation tried to model the room impulse response (RIR).

However, RIRs change quickly with speaker position, and are

nearly impossible to track accurately. Instead, we build a 3-D

model of the room, which we use to predict early reflections, which

are then incorporated into the SSL estimation. Simulation results

with real and synthetic data show that even a simplistic room

model is sufficient to produce significant improvements in range

and elevation estimation, tasks which would be very difficult when

relying only on direct path signal components.

UsingReverberation.pdf
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In  IEEE Transactions on Audio, Speech, and Language Processing

Publisher  Institute of Electrical and Electronics Engineers, Inc.

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