Abstract:

Objective: To compare the V. wave latencies, amplitudes, and testing times of auditory brainstem response (ABR) using Click and CE-Chirp stimuli in patients with unilateral total hearing loss (HL). Materials and Methods: Male patients with one normal ear and a total HL in the other were tested for Click and CE-Chirp ABR, Pure Tone Audiometry (PTA), Stenger, and Tympanometry. PTA thresholds in normal hearing ears were 20 dB HL for each frequency, tympanogram resulted to type A, and Stenger was negative in total HL. Click and CE-Chirp stimuli were sent using an alternating polarity and inserting ER 3A headphones (Rate: 20.1, High Pass Filter: 100 Hz, and Low Pass Filter: 3,000 Hz). Ear with total HL tested with 100 dB and 95 dBnHL, normal hearing ear was tested with 80, 60, 40, 30, 20, and 10 dBnHL, 15 dB, and 5 dBnHL to determine the hearing level. ABR thresholds, V. wave latencies, amplitudes, and test times for each Click and CE-Chirp stimuli were compared. Results: Results of 71 patients were analyzed. The CE-Chirp ABR wave V amplitudes were higher at all levels except 80 dBnHL. Click ABR wave V latencies at 80 and 60 dBnHL levels were longer (p=0.00). CE-Chirp ABR wave V latencies at 40 dBnHL and below were longer (p=0.00). CE-Chirp ABR thresholds (12.81 dBnHL) were closer to 2-4 kHz behavioral threshold averages (10.45 dBnHL) than Click ABR thresholds (14.64 dBnHL). CE-Chirp ABR test time was shorter (14.57±3.83 vs. 17.91±3.94 min, p=0.00). Conclusion: The CE-Chirp stimulus was used to evaluate the normal hearing ear in patients with unilateral total HL, which shortens the test time and provides closer results to behavioral thresholds. CE-Chirp ABR method is more advantageous than the Click ABR method to evaluate patients with unilateral total HL.

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