Sound Source Localization (SSL) based on microphone arrays
has numerous applications, and has received significant
research attention. Common to all published research is the observation
that the accuracy of SSL degrades with reverberation.
Indeed, early (strong) reflections can have amplitudes similar
to the direct signal, and will often interfere with the estimation.
In this paper, we show that reverberation is not the enemy, and
can be used to improve estimation. More specifically, we are
able to use early reflections to significantly improve range and
elevation estimation. The process requires two steps: during
setup, a loudspeaker integrated with the array emits a probing
sound, which is used to obtain estimates of the ceiling height,
as well as the locations of the walls. In a second step (e.g.,
during a meeting), the device incorporates this knowledge into
a maximum likelihood SSL algorithm. Experimental results on
both real and synthetic data show huge improvements in range