Texas Instruments Corporation

Wai-Ming Lai

Vishu R Viswanathan

Alan V McCree

Erdal Paksoy

Basavaraj I Pawate

Michael W Macon

Wallace Anderson

Rabin Deka

An improvement in the synthesis of high-pitched voices and sounds is provided by downshifting the pitch of the original input voice or sound before LPC analysis This downshifting of the pitch is provided by upsampling low pass filtering , downsampling and performing time scale modification

Synthesis of high-pitched sounds

A synthesis of percussion musical instruments sounds is provided using a microprocessor (17) that implements an all pole lattice filter and applying either a single impulse signal to the filter or N samples of an excitation signal sequence to the filter by a memory (19). The coefficients of the filter are determined by storing digital samples (501) of desired musical note from a desired percussion instrument, generating a Fourier transform to get a spectrum (502), picking the peaks of the spectrum (503) to select the most prominent components in the spectrum and determining wanted frequencies for decaying sine waves and for the frequencies finding the time envelope and estimating therefrom the pole radius.

Synthesis of percussion musical instrument sounds

A synthesizer may synthesize speech by receiving an adaptive codebook excitation signal and an adaptive codebook gain. The adaptive codebook excitation signal may be scaled using the adaptive codebook gain to generate a scaled adaptive codebook excitation signal. A fixed excitation signal and a fixed excitation gain may also be received. The fixed excitation signal may be scaled using the fixed excitation gain to generate a scaled fixed excitation signal. The scaled adaptive codebook excitation signal and the scaled fixed excitation signal may be combined to generate the excitation signal having a first word length. An overall gain signal of the excitation signal may also be received. A scaled excitation signal may then be generated by scaling the excitation signal using the overall gain signal. The scaled excitation signal may have a second word length greater than the first word length.

Synthesizer and method using scaled excitation signal

A Karaoke (10) apparatus with autokeying is provided by measuring the average pitch (28) of the singer or user over a predetermined time period, comparing (29) the pitch of the singer or user voice to that of a reference pitch to provide a signal representing mismatch and changing the pitch (31) of the background music to match that of the singer or user.

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Dallas, TX, United States of America

Wai-Ming Lai