DPOAE-grams in patients with acute tonal tinnitus.Otolaryngol Head Neck Surg. 2005 Apr; 132(4):550-3.OH
To investigate cochlear outer hair cell function in patients with acute tonal tinnitus and normal or near-normal hearing threshold.
STUDY DESIGN AND SETTING
Prospective controlled study in an academic tertiary health center. Distortion products of otoacoustic emissions (DPOAE)-grams of 32 ears with acute tonal tinnitus and normal hearing or minimal hearing loss were compared with those of 17 healthy nontinnitus ears.
Tinnitus ears exhibited relatively increased amplitudes of DPOAE at high frequencies (4-6.3 kHz) when compared with the group of healthy ears and relatively decreased DPOAE amplitudes at middle frequencies (1650-2400 Hz). Statistically significant (P < 0.01) increased mean values of DPOAE amplitudes were observed only at a frequency of f2 equal to 4.9 kHz.
CONCLUSIONS AND SIGNIFICANCE
These findings suggest an altered functional state of the outer hair cells at a selected high-frequency region of the cochlea in ears with acute tonal tinnitus and normal or near-normal hearing threshold.