Translators with External Phosphors

Two translators are described which display instantaneously on a moving external phosphor the essential characteristics of sound waves, such as speech. There is thus presented to the eye a parade of speech patterns as though a printed line were passing by. The pattern of intensity vs. frequency vs. time remains in view long enough to permit the eye to observe pattern groups as an aid to speech interpretation. Typical applications are portraying the phonetics of speech and aiding the deaf to understand speech and to build up their own speech. The goal in the speech pattern portrayal is to show the stronger speech components simply but accurately as a function of frequency and time. The speech is equalized to bring out the stronger components over the frequency range. Next automatic volume control is applied to iron out level differences on a time basis. Then the 3500 cycle speech band is analyzed by twelve filters of about 300 cycles each and the resultant component powers applied to the excitation of a phosphor. The smaller translator employs twelve incandescent grain-of-wheat lamps for phosphor excitation, generating a pattern 1″ high and 5″ long and the larger translator sets up a pattern 7″ high and 47″ long. The patterns remain in the field of view for about two seconds.