An observer-based psychoacoustic procedure for use with young infants.

Abstract

This article describes an observer-based technique for assessing auditory capacities of infants from 3 to 12 months of age. This technique, referred to as the Observer-based Psychoacoustic Procedure (OPP), combines features of the Forced-choice Preferential Looking technique developed by Teller (1979) and of Visual Reinforcement Audiometry (Moore; Thompson, & Thompson, 1975). The rationale behind the procedure and the specific techniques used in its application are detailed here. Psychometric functions and thresholds for pure-tone detection and frequency discrimination ob-tained with OPP are also presented. The results for 6-month-olds are compared with results from previous studies employing a visually reinforced head-turn procedure. The number of studies of infant hearing development has in-creased dramatically in the past 10 years. Infant absolute audi-tory sensitivity has been examined in several laboratories (e.g., Berg & Smith, 1983; Sinnott, Pisoni, & Aslin, 1983; Trehub, Schneider, & Endman, 1980). Frequency and intensity differ-ence thresholds have been estimated (e.g., Olsho, 1984b; Sin-nott & Aslin, 1985). The infant's ability to detect sounds in the