52 July 1994 AJA Article 1059-0889/94/0302-0052 © American Speech-Language-Hearing Association Wave I latencies were used to predict the magnitude of conductive components in 80 infants and young children (122 ears) with normal hearing, conductive hearing loss due to otitis media or aural atresia, sensorineural hearing loss, and mixed hearing loss. Two prediction methods were used. The first method based predictions on a 0.03-ms wave I latency delay for each decibel of conductive hearing loss. The second method was based on a regression analysis of wave I latency delays and the magnitude of conductive component for the subjects in this study with normal cochlear status. On average, these prediction methods resulted in prediction errors of 15 dB or greater in over one-third of the ears with hearing loss. Therefore, the clinical use of wave I latencies to predict the presence or magnitude of conduc- tive impairment is not recommended for infants and young children. Instead, bone-conduction ABR testing is recommended as a direct measure of cochlear status when behavioral evaluation is not possible. A udiologists involved in the assessment of hearing in infants and difficult-to-test patients are often unable to obtain reliable behavioral information regarding hearing sensitivity. In such instances, auditory brainstem response (ABR) testing is used to obtain further information. As in any hearing evaluation, when a hearing loss is identified through ABR testing, it is important to estimate the degree of cochlear involvement. In behavioral testing, this is normally accomplished through bone- conduction testing; however, bone-conduction ABR testing is not routinely done in the clinic. Latency measures obtained from the ABR to air-con- ducted stimuli provide a potential source of information not available from the behavioral air-conduction audiogram. Latencies increase as stimulus intensity decreases (for review, see Hall, 1992, pp. 126–133), and conductive hearing loss reduces the effective intensity arriving at the cochlea. Consequently, ABR latencies are often prolonged in cases of conductive hearing loss. It is a commonly held belief that these ABR latency shifts can be used to predict the extent of conductive involvement with reasonable accuracy. The relationship between ABR latency and the magni- tude of conductive loss has been examined for both wave I (Berlin & Gondra, 1976; Chisin, Gafni, & Sohmer, 1983; Conijn, van der Drift, Brocaar, & van Zanten, 1989; Eggermont, 1976; Fria & Sabo, 1979; Mendelson, Salamy, Lenoir, & McKean, 1979; Salomon & Elberling, 1988) and wave V (Borg, Löfqvist, & Rosén, 1984; Chisin et al., 1983; Conijn et al., 1989; Fria & Sabo, 1979; McGee & Clemis, 1982; van der Drift, Brocaar, & van Zenten, 1988; van der Drift, van Zenten, & Brocaar, 1989; Yamada, Yagi, Yamane, & Suzuki, 1975). There are at least two methods that have been used to predict conductive hearing loss using wave I and wave V latency delays. One method is based on the horizontal shift from the normal wave I or V latency-intensity (LI) function. For example, Yamada et al. (1975) extended a horizontal line from the latency value at normal threshold (10 dB for their subjects) to the point of intersection with the subject’s LI function, and then calculated the difference (in dB) between the normal threshold and the intensity at the point of intersection. A second method, using wave I latency, estimates the magnitude of the conductive component from the latency delay at a single intensity, where each 0.3-ms delay from the mean of normal latency values corresponds to 10 dB of conductive loss (Fria & Sabo, 1979). Results from these studies have been mixed. Predictions for ears with known conductive hearing loss have been reasonably good. For example, van der Drift et al. (1989) reported that predictions of magnitude of conductive loss Auditory Brainstem Response Wave I Prediction of Conductive Component in Infants and Young Children Carol L. Mackersie David R. Stapells Albert Einstein College of Medicine, Bronx, NY City University of New York