HIGH-FREQUENCY AUDIOMETRY - RESPONSE CHARACTERISTICS OF THE KH70 VIBRATOR

Various response characteristics of the Pracitronic KH70 bone vibrator have been investigated in the frequency range 0.25 through 16 kHz. Masked threshold reproducibility is satisfactory throughout the frequency range. An occlusion effect is present only at frequencies at and below 1 kHz. Stimulus perception lateralizes to the occluded ear through 1 kHz and less consistently at successively higher frequencies. The KH70 does not satisfy the IEC 645 (1979) criterion for acoustic radiation for frequencies below 6 kHz, especially at the intermediate frequencies of 0.5, 1 and 2 kHz. With the restrictions inherent in the occlusion effect, this does not, however, interfere with threshold determination. The vibrator would thus seem suitable for clinical use through 16 kHz.