A Direct‐Reading Pitch Recorder and Its Applications to Music and Speech

An electrical arrangement was devised, by means of which rapid variations in pitch with time, such as occur in music or speech, could be directly recorded even in detail. The arrangement consisted of amplifiers, a wave form adjuster, an automatic volume control, and a frequency meter. The frequency meter itself is essentially the same as the two‐tube thyratron inverter, which was first described by Hull as one of the applications of thyratron, and recently modified by Hunt. Efforts were made to utilize the frequency meter in conjunction with the wave form adjuster and the automatic volume control in order to make it suitable for indicating the rapid pitch variations, accompanied by large intensity variations, in music as well as in speech. The final indication of pitch is made in logarithmic scale, several applications of the arrangement to music and speech being given.