Browse Prior Art Database

Noise Compensating Amplifier/Mixer

IP.com Disclosure Number: IPCOM000123214D
Original Publication Date: 1998-Jul-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 42K

Publishing Venue

IBM

Related People

Ball, MR: AUTHOR

Abstract

Disclosed is a device to automatically adjust audio level outputs in multimedia applications such as kiosks located in public locations such as shopping malls, airports, train stations, hotel lobbies, etc. The level of ambient noise in public areas can vary widely throughout the day. When the area is busy and the ambient noise level is high, the volume of the current multimedia application may be too low, and when the area is closed and deserted, the volume may be too high. Current solutions force the user to set the volume each time the application is used, or in applications without volume control, a single volume setting must be chosen at manufacture. The device provides an automatic, unobtrusive volume control in the form of a noise compensating amplifier/mixer.

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Noise Compensating Amplifier/Mixer

   Disclosed is a device to automatically adjust audio level
outputs in multimedia applications such as kiosks located in public
locations such as shopping malls, airports, train stations, hotel
lobbies, etc.  The level of ambient noise in public areas can vary
widely throughout the day.  When the area is busy and the ambient
noise level is high, the volume of the current multimedia
application may be too low, and when the area is closed and
deserted, the volume may be too high.  Current solutions force the
user to set the volume each time the application is used, or in
applications without volume control, a single volume setting must be
chosen at manufacture.  The device provides an automatic,
unobtrusive volume control in the form of a noise compensating
amplifier/mixer.

   The amplifier/mixer unit uses a microphone to sense the
levels of the audio output of the multimedia application and the
ambient noise.  It subtracts the audio output and analyzes the
ambient noise using a psycho-acoustic algorithm.  The audio output
level is adjusted based on the level of ambient noise and its
frequency spectrum.  In a preferred embodiment, four independent
stereo inputs are provided and the levels on the left channels can be
adjusted independently to provide consistent output levels for all
input sources.

   The unit has two modes of operation.  In "smart" mode, the
system reacts to ambient noise and adjusts the audio output level as
re...