Treatment of High Tone Deafness with Electric-Natural Stimulation (ENS) - Audiological Results

Introduction In the treatment of CI patients with high frequency hearing loss, high frequencies are electrically stimulated and, depending on the hearing threshold, low frequencies are acoustically amplified. Electric-acoustic stimulation (EAS) amplifies the low-frequency residual hearing via an ear mould, whereas patients with a sufficient hearing threshold in the low-frequency range can abstain from acoustic amplification and use normal hearing via electric-natural stimulation (ENS). This study is based on the evaluation of the effectiveness of ENS.

Methods Depending on hearing ability, MED-EL FLEX electrodes of different lengths were implanted at the Hannover Medical School (MHH) and the insertion depth (IED) determined by imaging. N=7 adults and N=1 children with ENS treatment were analyzed retrospectively. The hearing preservation after implantation was considered and the intersection of the postoperative auditory threshold at ≤30dB HL was selected as start frequency of the electrical stimulation in the MED-EL Maestro Software. Hearing performance in quiet and in noise was measured using the Freiburg Monosyllabic Test (65dB) and the HSM Sentence Test (10dB SNR).

Results At the time of initial fitting, median hearing loss was 8.8 dB in adults (N=7, median IED=19.13 mm) and 7 dB in a child (N=1, IED=17.21 mm). N=4 adults were supplied with ENS at a median electrical crossover frequency of 450 Hz since initial fitting. At the end of the first fitting week they achieved a median speech understanding of 32.5% in quiet and 56.5% in noise.

Conclusion In the case of sufficiently good residual hearing in the low-frequency range ≤30dB HL, the ENS treatment leads to good speech intelligibility at rest and in background noise in both adults and children.

Poster-PDF A-1729.PDF

Publication History

Article published online:
10 June 2020