Patent Document ID: 4754485
Application ID: 06560221

Base Claim:
1. In a system for transforming first digital signals representing text into an analog waveform signal, said system comprising first processing means for transforming said first digital signals into second digital signals representing a plurality of speech parameters, second processing means for transforming said second digital signals into third digital signals representing a first predetermined number of samples per second of a digitized glottal waveform, third processing means for forming fourth digital signals representing a digitized combined waveform from at least said third digital signals and fifth digital signals representing digitized sound waveforms other than said digitized glottal waveform, and means for converting said fourth digital signals into said analog waveform signal, the improvement wherein said second processing means comprises means for generating sixth digital signals representing a second predetermined number of samples per second of a digitized glottal waveform as a function of said second digital signals, means for low pass filtering said sixth digital signals to form seventh digital signals representing a digitized glottal waveform with frequencies above a predetermined threshold frequency removed, and means for down-sampling said seventh digital signals to form said third digital signals, wherein said second predetermined number of samples per second is greater than twice said predetermined threshold frequency.

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Claim 2:
2. They system as defined in claim 1, wherein said means for generating fourth digital signals comprises a first computer program, said means for low pass filtering comprises a second computer program, said means for down-sampling comprises a third computer program, and said second processing means further comprises means for storing said first, second and third computer programs.