Conversionless digital speech production
First Claim
1. Apparatus for producing speech from digitally encoded speech samples without the use of a digital-to-analog converter, comprising:
- (a) speech computation means for producing a sequence of digitally encoded samples representing the waveform of speech to be produced;
(b) a computer central processing unit;
(c) a speaker; and
(d) control means for applying to said speaker a square wave signal having a duty cycle controlled by said speech computation means in accordance with the speech to be produced;
(e) said square wave signal having a constant frequency in the ultrasonic range.
3 Assignments
0 Petitions
Accused Products
Abstract
Clear speech can be produced on a DAC-less personal computer from an all-software speech-generating program with an unlimited vocabulary by applying to the computer'"'"'s speaker a square-wave carrier signal of ultrasonic frequency, and varying the duty cycle of the carrier signal in accordance with digitized speech samples to produce an audio signal. The computations necessary to produce the speech samples are so timed by the program that the CPU is free to turn the speaker on and off between computations at precisely the right instant for the correct generation of a carrier having a constant ultrasonic frequency and a duty cycle determined by the value of the speech samples.
8 Citations
5 Claims
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1. Apparatus for producing speech from digitally encoded speech samples without the use of a digital-to-analog converter, comprising:
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(a) speech computation means for producing a sequence of digitally encoded samples representing the waveform of speech to be produced; (b) a computer central processing unit; (c) a speaker; and (d) control means for applying to said speaker a square wave signal having a duty cycle controlled by said speech computation means in accordance with the speech to be produced; (e) said square wave signal having a constant frequency in the ultrasonic range. - View Dependent Claims (2, 3, 4, 5)
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Specification