Multihandicapped children's preferences for pure tones and speech stimuli as a method of assessing auditory capabilities.

Residual hearing capabilities of nine severely and profoundly retarded multihandicapped deaf-blind children were determined with an operant procedure that allowed the children to respond by making a selection between two alternative responses. One response option resulted in the presentation of auditory reinforcement (pure tones and speech stimuli of various frequencies); the other option resulted in no reinforcement. Levels of the sound intensity were varied systematically to obtain a "threshold" for selective responding. Each of the severely damaged "untestable" children made numerous meaningful responses throughout the testing sessions, thereby revealing the levels of intensity that could be heard and those that were not high enough to elicit preferential responding. The children responded comparably in conditions employing pure tones and speech. The responses of most of the children were comparable across frequency conditions, although some of the children's records show selective responding at lower levels of intensity for certain frequencies than for others. We also found that varying the level of intensity of the stimuli not only affected the children's selective behavior, but also their time on task measures and their individual patterns of responding.