The simplified HF E-800 audiometer: calibration and normative aspects.

Abstract

Although numerous viable applications of high frequency (HF) audiometry have been demonstrated in the past 20 yrs, a set of specifications analogous to those for diagnostic pure-tone audiometers (ANSI, 1969) is lacking. Thus, meaningful interpretation of HF thresholds must consider the system employed to assess auditory sensitivity. A cost-effective HF audiometer has recently been described based on the Grason-Stadler E-800 Bekesy audiometer in the fixed-frequency mode. Preliminary results indicate highly acceptable reliability and validity of thresholds. In the present study, 20 men and 65 women, all normally hearing young adults (170 ears) presenting with negative otoaudiologic histories produced HF ac thresholds from 8-20 kc/s. Excursion widths of pen tracings compared favorably with those of earlier reports in HF audiometer studies. The composite function (both sexes, both ears) was flat through 12 kc/s, with progressively greater SPLs required for higher frequencies. Neither gender nor ear-related differences were seen. Calibration was performed using the NBS 9 A 6-cc coupler and the manufacturer's flat-plate coupler for the Koss HV/X stereophone used. Conversion factors were presented so that either coupler could be used. A threshold function was recommended for use consisting of the composite median function for 170 ears. It was concluded that the Simplified HF E-800, or an analogous unit, could be used as a viable clinical tool, surpassing the cost effectiveness of a number of different HF audiometric systems.