Advantages of Narrow Band CE-Chirp ABR Compared to Tone Burst ABR in
Adults with Normal Hearing
Abstract
Objectives: In this study, we aimed to compare the ABR’s (Auditory
Brainstem Response) estimated behavioral thresholds, wave V latencies,
and amplitudes, obtained using Tone Burst and Narrow Band (NB) CE-Chirp
stimuli in adults with normal hearing. Design: A prospective study was
designed. Setting: Otorhinolaryngology and Audiology Clinic of the
tertiary university. Participants: Twenty-four adults with normal
hearing (17 males, 7 females) participated in this study. Main outcome
measures: ABR was recorded using Narrow Band (NB) CE-Chirp and Tone
Burst (TB) for four frequencies (0.5, 1, 2, 4 kHz). Wave V obtained for
60, 40, and 20 dB nHL intensity levels for both two procedures.
Behavioral hearing thresholds (BHT) were identified at 0.5, 1, 2, 4 kHz.
Duration of TB and NB CE Chirp ABR tests for each ear was recorded. Wave
V latencies, amplitudes, BHTs, duration of tests were compared. Results:
The thresholds obtained from NB CE-Chirp stimulus (20, 19, 16, 15 dB
nHL) at 0.5, 1, 2 and 4 kHz were significantly closer to the behavioral
hearing thresholds (11, 10, 9, 9 dB HL) compared to Tone Burst ABR
thresholds (25, 23, 20, 19 dB nHL) (at all frequencies p <
0.001, CI = 2.0- 5.9). The absolute latencies of peak V with TB stimuli
were significantly longer than latencies obtained with NB CE Chirp
stimuli at 0.5, 1, and 2 kHz at all sound intensity levels
(p<0.001). The mean test time for NB CE-Chirp ABR was 23.6 ±
3.9 minutes and significantly shorter than the TB ABR test time (28.2 ±
4.5), (p=0.011). Conclusion: Frequency-specific behavioral thresholds
are estimated better with NB CE-Chirp than TB ABR.