[Analysis of evoked otoacoustic emission in normal pure tone hearing thresholds patients with aural fullness].

OBJECTIVE

To analyze normal pure tone hearing thresholds patients with aural fullness using evoked otoacoustic emission in order to detect the early cochlear impairment.

METHOD

Forty-three normal pure tone hearing thresholds patients (72 ears, aural fullness group) with aural fullness were served as subjects and 30 normal volunteers (60 ears, control group) as controls. Transiently evoked otoacoustic emission (TEQAF) and distortion product evoked otoacoustic emission (DPOAE) were tested with Capella otoacoustic emission machine. The DPOAE detection rate and amplitudes at all frequencies,the passing rate and wave signal noise ratio (SNR) ,wave reproducibility, band SNR and band reproducibility of TEOAE were recorded and analyzed.

RESULT

(1) Only on the frequency points of 0.50 kHz and 0.75 kHz, the detection rate of DPOAE in aural fullness group was lower than that in control group (P < 0.05). There was no significant difference in the rate among other frequency points (P > 0.05). (2) The passing rate of TEOAE was 100w in control group and 90. in aural fullness group. There were statistical differences between two groups (chi2 = 6.16, P < 0.05). (3) Compared with the control group, the DPOAE amplitudes at all frequencies, the wave signal noise ratio (SNR), wave reproducibility, band SNR and band reproducibility of TEOAE in patients with aural fullness were significantly decreased. There were statistical differences (P < 0.05 or P < 0.01).

CONCLUSION

Some patients of normal hearing thresholds with aural fullness have had early harm of Outer hair cell in cochlear. TEOAE and DPOAE may he used to detect these lesions early before the hearing impairment occurred.