Patent ID: 6449370
Filing Date: 2002-09-10
Classification: H04R

Abstract:
A digital electro-acoustic transducer comprising:a plurality of sound generating units for converting electrical signals into sounds; at least one sound receiving unit for producing an output signal in accordance with sound pressure exerted on a vibration film; a housing having a cavity in which said plurality of sound generating units and said at least one sound receiving unit are accommodated, wherein said housing is soundproof and said plurality of sound generating units and said at least one sound receiving unit are accommodated on the same plane in said cavity of said housing; driving means for driving said plurality of sound generating units on the basis of a drive signal; modulation means for sampling an output signal of said at least one sound receiving unit to produce a pulse in accordance with variation in amplitude of said output signal; and drive signal preparation means for calculating an arithmetic signal which reduces the amplitude of the output signal of said at least one sound receiving unit on the basis of the pulse supplied from said modulation means and superposing an externally supplied digital audio signal on said arithmetic signal to prepare said drive signal to be supplied to said driving means.