Speech Enhancer for Group Conversation in Noise - Project Summary/Abstract
Background noise is an impediment to conversation for everyone, but for those with hearing
loss, noise can be a terrible source of confusion, frustration, and social isolation. The problems
of conversing in noise are all too familiar not only for people who have hearing aids or cochlear
implants, but also for the millions of people with moderate hearing losses, many of them older
than 65 years. This is especially troubling in restaurants or a retirement home's dining hall,
which provide pivotal occasions for social interaction. The goal of this project is to develop a
low-cost assistive listening device that will make it easy to participate in conversations in noisy
environments. The focus is on a device that does its designated task well rather than a system
overloaded with extraneous features that detract from its primary purpose. Current wireless
assistive listening devices for such situations allow one person to receive enhanced speech
signals from multiple talkers, and so do not provide assistance to more than one person in a
group. Multi-way communication systems that allow communication among all participants cost
more than $1000, making them too expensive for common use. In the proposed system, each
person in a group wears a wireless earset with a boom microphone and earphone (similar in
form to Bluetooth devices worn on one ear). Speech signals picked up by each microphone are
transmitted by radio and processed in such a way that all persons in the group can hear each
other as in a conference call. If two or more people speak at the same time, listeners in the
group hear the voices overlap naturally. The benefit for speech reception arises from the
proximity of the microphone to the talker's mouth, which increases the signal-to-ambient noise
ratio by up to 20 dB over that received acoustically at a listener's ear. This figuratively
corresponds to speaking directly into every group member's ear at a distance of a few
centimeters. The expected ease of operation and low cost of these devices makes them ideal
for general use at family gatherings and meals, retirement homes, and restaurants, not only for
people with hearing loss but anyone wishing to more easily participate in conversations. Work in
Phase I will focus on circuit design to maximize audio performance with minimal size, cost, and
power drain, as well as ergonomic design for ease of use. Tests of speech intelligibility in noise
will be performed to quantify the benefit to the user. The operational simplicity of this approach
will lead to a low-cost and easy-to-use assistive listening product to improve the quality of life of
millions of people, especially those with impaired hearing.
