SPEECH BANDWIDTH REDUCTION.
Final technical rept. Mar 65-Jun 66,
PHILCO BLUE BELL PA ADVANCED COMMUNICATIONS LAB
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This report presents experimental results, comclusions, and recommendations resulting from research - conducted on a speech bandwidth reduction technique based on an electrical analog of the human hearing mechanism. This research centered around the Single Equivalent Formant SEF technique whereby it is hypothesized that intelligent speech could be transmitted with three parameters SEF frequency, amplitude, and pitch. This was partially proven in that the intelligence RT word score was measured at 75 percent for experienced speakers and listeners. However, the machine-like quality of the synthesized speech proved to negate the systems use with all but highly trained operators. Three other systems, including resynthesizing three formant speech from the SEF parameter using storage, were investigated. The system that was finally decided upon as the closest to meeting the goals is a two formant, three amplitude, and pitch system with 120 Hz bandwidth. This system has a measured RT score of 85 percent and the quality is adjudged to be quite human-like. Transmission of the parameters is accomplished.
- Voice Communications