2 research outputs found
Robust Sound Source Localization Using a Microphone Array on a Mobile Robot
The hearing sense on a mobile robot is important because it is
omnidirectional and it does not require direct line-of-sight with the sound
source. Such capabilities can nicely complement vision to help localize a
person or an interesting event in the environment. To do so the robot auditory
system must be able to work in noisy, unknown and diverse environmental
conditions. In this paper we present a robust sound source localization method
in three-dimensional space using an array of 8 microphones. The method is based
on time delay of arrival estimation. Results show that a mobile robot can
localize in real time different types of sound sources over a range of 3 meters
and with a precision of 3 degrees.Comment: 6 page
Robust Recognition of Simultaneous Speech By a Mobile Robot
This paper describes a system that gives a mobile robot the ability to
perform automatic speech recognition with simultaneous speakers. A microphone
array is used along with a real-time implementation of Geometric Source
Separation and a post-filter that gives a further reduction of interference
from other sources. The post-filter is also used to estimate the reliability of
spectral features and compute a missing feature mask. The mask is used in a
missing feature theory-based speech recognition system to recognize the speech
from simultaneous Japanese speakers in the context of a humanoid robot.
Recognition rates are presented for three simultaneous speakers located at 2
meters from the robot. The system was evaluated on a 200 word vocabulary at
different azimuths between sources, ranging from 10 to 90 degrees. Compared to
the use of the microphone array source separation alone, we demonstrate an
average reduction in relative recognition error rate of 24% with the
post-filter and of 42% when the missing features approach is combined with the
post-filter. We demonstrate the effectiveness of our multi-source microphone
array post-filter and the improvement it provides when used in conjunction with
the missing features theory.Comment: 12 page