The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 18, 1998
Filed:
Sep. 01, 1995
Abstract
A sound reproduction apparatus for a vehicle comprises: a sound source for generating a sound signal; a sound reproduction portion for reproducing a sound from the sound signal into a compartment of the vehicle; a microphone, provided in the compartment, for detecting the sound transmitted in the compartment and environmental sound noise and for generating a sound detection signal; a detection portion for detecting a magnitude of the environmental sound noise by detecting a difference between magnitudes of the sound signal and the sound detection signal; and a volume control portion for effecting volume controlling of the sound signal according to the magnitude of the environmental sound noise from the detection portion. An equalizing portion substantially equalizing gains of signal paths of the sound signal and sound detection signal supplied to the detection portion in a substantially silent condition of the compartment is provided. For accurate equalizing of gains, a reference sound signal source is provided. A part of frequency range of the sound signal is enhanced according to the sound noise. The volume controlling with the environmental sound noise is modified according to a peak level, an external volume control signal. The noise level may be classified. A large change in the volume within a short interval is avoided.