Amplivox Transistorized Auditory Training Amplifier This Amplivox Auditory Training amplifier was probably used for speech training for children with severe and profound hearing losses. It originally used batteries of unknown size since it is of English manufacture. It was probably made in the 1960s. The left knobs controlled the gain from the record player (radiogram in Britain) for prerecorded speech, while the right knobs controlled the gain from the microphone for live speech input. | 
