Apparatus for speech pattern derivation

The invention relates to the monitoring, recording and display of a speaker's larynx waveform, for the purposes of education, speech therapy and speech analysis. A pair of electrodes are applied externally to the larynx region of the speaker's neck. Each electrode has two concentric surfaces (the outer surface is called a guard ring). One electrode feeds a carrier voltage to the speaker's neck. The other electrode receives the resultant larynx amplitude-modulated current. Detection techniques are used to derive the larynx waveform. A preferred detection technique is "slicing" which is herein defined as a demodulation which follows the changes in envelope of an amplitude-modulated carrier and retains only the small rapid larynx modulation filtering out the slower neck-movement modulation. The important feature of speech called intonation, which is made up of rhythm and pitch patterns, is directly correlated with larynx frequency. The present larynx waveform provides a simple and reliable basis both for the representation of intonation in speech and for the analysis of the frequencies defining other speech pattern features. Any combination of these patterns is displayed, on a domestic television receiver, for instance, and, or plotted or recorded.