Short-term observation of electrical acoustic stimulation in patients with low frequency residual hearing after cochlear implant

Abstract

Objective: To analyze the effects of electrical acoustic stimulation (EAS) on speech and tone recognition as well as music perception in children with low-frequency residual hearing (LFRH) after cochlear implant (CI). Methods: A total of twelve Mandarin patients with LFRH who underwent unilateral CI from January 2017 to October 2020 were recruited, including 8 males and 4 females. There were 5 cases of pre-lingual deafness and 7 cases of post-lingual deafness. The median age at implantation was 12 years old (3-62 years). All patients had residual hearing (RH) before surgery, wore hearing aid (HA) timely, had an effective rehabilitation and the duration of use of electrical stimulation was 37.0±16.2 months. On the implanted side, the thresholds of 125 Hz and 250 Hz were less than and equal to 80 dB HL after implantation. A two-month follow-up clinical study was conducted with the EAS devices. The EAS effects were evaluated before, immediately after and 2 months after upgrade, including speech recognition rate, tone recognition and music tests. SPSS 23.0 software was used for statistical analysis. Results: A total of ten patients completed a two-month clinical follow-up and efficiency evaluation. Compared to the electrical stimulation, the recognition rate of spondee word significantly decreased after the immediate use of EAS (71.7±4.3 vs 79.6±3.1, P=0.018). Compared to the electrical stimulation as well as immediate use of EAS, the results of sentence in noise, tone in noise, and SRT of sentence in noise were all significantly improved at 2 months after use of EAS (P<0.05). The pitch discrimination was significantly improved at 2 months after the use of EAS compared with that before the use of EAS (P=0.042). Compared with before (P=0.021) and immediately (P=0.017) use of EAS, the ability of rhythm resolution was significantly improved. There were no significant differences in other test results (P>0.05). Conclusions: The low-frequency acoustic information provided by EAS as well as the electrical-acoustic stimulation mode can provide rich auditory cues of speech perception in noise, tone recognition in noise, and musical discrimination for CI subjects. It can promote the improvement of complex listening ability of CI patients undergoing long-term electrical stimulation in a short time and comprehensively improve their hearing capacities.