STEADY-STATE EVOKED-POTENTIAL AND BEHAVIORAL HEARING THRESHOLDS IN A GROUP OF CHILDREN WITH ABSENT CLICK-EVOKED AUDITORY BRAIN-STEM RESPONSE

Objective: 1) To examine the distribution of behavioral hearing thresh olds in a group of children who had shown no click-evoked auditory bra in stem response (BBB) at maximum presentation levels, 2) To describe the relationship between the 90 Hz steady-state evoked potential (SSEP ) and behavioral thresholds in these subjects, Design: A retrospective study based on clinical findings obtained from 108 infants and young children, Each of these children had shown no recordable ABR to clicks presented at maximum levels (100 dB nHL). SSEP audiograms were obtain ed using AM/FM tones at the octave frequencies 250 to 4000 Hz. The res ults of these evoked potential assessments mere compared with hearing thresholds established behaviorally. Results: Click-ABR assessment cou ld not differentiate between the subjects in our sample with total hea ring losses anti. those with useful residual hearing. Although some of the ears were anacusic, more than a quarter showed residual hearing a l; each of the audiometric frequencies. Furthermore, at least 10% of t he behavioral thresholds at each frequency fell. within the moderate/s evere hearing loss range, A far closer relationship was observed betwe en SSEP and hearing thresholds. On occasions where the SSEP was absent at maximum levels, 99.5% of the ears showed either a total loss or a behavioral threshold within 10 cll: of that level. When an SSEP was ob tained, the hearing threshold was typically within 5 dB of the SSEP th reshold. Conclusion: The results suggested that in our group of select ed subjects, the SSEP technique was able to assess ears with only mini mal amounts of residual hearing, Where the brevity of the acoustic cli ck limits both its frequency specificity and its presentation level, t he modulated tones used for SSEP testing allow accurate, frequency-spe cific assessment at high presentation levels.