A Signalling Device for Non-Oral Communicators

Partially speaking students and users of augmentative/alternative communication systems commonly benefit from a method of signalling to initiate or repair their communicative efforts. This article describes a simple way of modifying a common, inexpensive 9-volt portable transistor radio to serve as a durable, cosmetically attractive audio oscillator signalling device that can be operated by a single external switch. The unit can still be used as a radio receiver in the usual fashion. Instructions for modification and use are described, with suggestions for switches and mounting.

Children's Phonatory Matching of Pure-Tone and Human Voice Stimulus

Thirty-six children were tested for their ability to vocally match both human voice and pure-tone stimuli. Spectrographic and statistical analysis of their tape-recorded responses revealed the majority of the children more closely approximated the human voice stimulus. The effects of age and sex of the children on their ability to match the two types of stimuli were also examined. The results of this study indicate that children are better able to match audiotape recordings of trained human voices modeling a wide range of calibrated frequencies than pure tones generated by an audio-oscillator.

Human Sound Frequency Preferences

205 subjects each chose a “most pleasant” sound delivered through an earphone by turning the control knob on a continuously variable audio oscillator. Most subjects chose a frequency in a relatively narrow (approximately 350 Hz) band centered on 399 Hz. The preferences did not appear to be influenced by sex or age.