Auditory evoked potentials on an inpatient basis in clinical practice

E.E. Savelieva¹, G.Sh. Tufatulin^2,3, E.S. Saveliev¹

¹Bashkir State Medical University, Ufa

²Children’s City Center of Surdology, Saint Petersburg

³North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg

Aim: to determine the association between psychoacoustic auditory thresholds and hearing thresholds obtained using the registration method of auditory steady-state response (ASSR).

Patients and Methods: ASSR registration during intra-earphone stimulation was performed in 76 children (152 ears) with sensorineural hearing loss (average age — 2.68±0.16 years) during physiological sleep. Stimuli modulated in amplitude and frequency (ASSR MM) were used, modulation frequency was 90 Hz. Chirp stimulus was used in 40 children. ASSR during stimulation in the auditory field was registered in 2 adults (25 and 30 years old) and 2 children (4 and 8 years old) with normal hearing. The study was conducted in an anechoic chamber. The modulation frequency was 40 Hz. Thresholds obtained using psychoacoustic methods and ASSR were compared.

Results: the ASSR MM thresholds most closely reached the psychoacoustic auditory thresholds with a marked degree of hearing loss  and deafness; in the I–III degrees of hearing loss, the difference between thresholds of the ASSR MM and psychoacoustic tests was increased. The average difference was at 500 Hz — 18.03 dB, at 1000 Hz — 15.46 dB, at 2000 Hz — 12.71 dB, at 4000 Hz —13.96 dB (r_s=0.73–0.79). When using the Chirp stimulus, the average difference between thresholds of ASSR and psychoacoustic tests was at 500 Hz — 8.94 dB, at 1000 Hz — 7.88 dB, at 2000 Hz — 5.63 dB, at 4000 Hz — 6.77 dB (r_s=0.85–0.88). Depending on the frequency, the difference between behavioral and electrophysiological thresholds in the auditory field varied from 0 dB to 35 dB, there was a correlation from r_s=0.75 to r_s=0.95 (p<0.05) in adults, and from r_s=0.55 to r_s=0.95 (p<0.05) in children. The maximum difference between behavioural and ASSR thresholds in the auditory field was observed at 500 Hz (average value — 15.6 dB), and the minimum — at 2 and 4 kHz (average values of 8 dB and 7 dB, respectively).

Conclusion: ASSR method allows to determine hearing thresholds that have a high correlation degree with behavioural thresholds. Thus, the preferred type is Chirp stimulus. Providing stimulus in the auditory field opens up potential opportunities for evaluating the effectiveness of the auditory prosthetics.

Keywords: hearing loss, hearing diagnostics, ASSR, auditory prosthetics effectiveness.

For citation: Savelieva E.E., Tufatulin G.Sh., Saveliev E.S. Auditory evoked potentials on an inpatient basis in clinical practice. RMJ. 2020;5:3–8.