A color display system of connected speech for the deaf

Abstract

The system is composed of a computer for processing speech, digital memories for temporarily storing speech parameters, and a color coder for converting the parameters into composite color video signals. The video signals are transmitted from an antenna and received by conventional color TV sets. In voiced segments of connected speech, three formant frequencies are made to correspond to signals of three primary colors as follows: blue, EB = F2/3F1; the red, ER = 5F1/F3; green, EG = 3F3/5F2. The pitch signal controls the brightness of the colors. In unvoiced segments, as in brightness changes, only black and white stripe patterns appear on the TV screen. The patterns of connected speech flow from the bottom to the top of the TV screen. According to visual tests using connected vowels, the following results caused by simultaneous contrast effects in color can be shown. (1) The transition bands between two vowels judged using colors are much narrower than those determined by acoustical parameters. (2)The colors of adjacent vowels are emphasized with respect to each other so that it is possible that the influence of coarticulation on speech parameters can be compensated visually.