Threshold of the Early Components of the Averaged Electroencephalic Response Determined with Tone Pips and Clicks During Drug-Induced Sleep

Abstract

The early components of the averaged electroencephalic response (AER) were elicited from eight adults by narrow-spectrum tone pips centered at 250, 1 000, and 4 000 Hz, and by wide-band clicks. Brief naps were induced with secobarbital. Stimuli at 0, 10, 20, and 30 dB above behavioral threshold were presented in random order for each frequency. Control conditions in which no acoustic stimuli were presented were also employed. Responses were stored on magnetic tape and later scored independently on a yes-no basis by two judges who employed predetermined response criteria. Threshold for hearing (50-percent response) as measured with the early components was 20 dB sensation level (SL) for 250 Hz tone pips, and at 10 dB SL for 1 000 and 4 000 Hz tone pips and clicks. Thus, threshold estimated with the early components of the AER from sleeping adults closely approximated their behavioral threshold

Key Words:

• Electric response audiometry (ERA)
• Averaged electroencephalic response (AER)
• Electroencephalic audiometry (EEA)
• Tone pips
• Sedatives for EEA
• EEA during sleep
• Early components of the AER
• Objective scoring procedures
• Threshold measures