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Background: Calculation of percentage hearing loss (pHV) from the pure-tune audiogram according to Röser in 1973 or from the speech audiogram according to Boenninghaus and Röser in 1973 is a method still applied for quantitative assessment of hearing. However, this is not common for the evaluation of postoperative results of implantable hearing systems. During the regular work-up after cochlear implantation (CI) in Germany, all necessary parameters are available for calculation of pHV either from categorical loudness scaling (pHV KLS ) or speech-recognition threshold (pHV FB )., Objective: The parameters pHV KLS and pHV FB are introduced and calculated from data available from clinical routine. Their potential applicability for assessment of the result of CI is evaluated., Materials and Methods: This study comprises retrospective chart review of audiological parameters from 66 CI procedures in one tertiary referral center. pHV KLS was calculated from the equal loudness curve 5 CU, pHV FB from the Freiburg speech test in free field., Results: While pHV KLS shows small variation, the variation in pHV FB is initially larger but decreases over time. Furthermore, starting from initial fitting, the mean pHV shows convergence over time. The difference between pHV FB and pHV KLS is positive and statistically significant., Conclusion: It is possible to calculate pHV KLS and pHV FB from routine data. A correlation of the difference between pHV FB and pHV KLS with successful CI performance seems plausible., (© 2023. The Author(s).)

Background: By using outcome prediction scores, it is possible to distinguish between good and poor performers with cochlear implants (CI) after CI implantation. The reasons for poor performance, despite good basic conditions, can be manifold. On the one hand, the postoperative fitting may be inadequate; on the other, neurophysiological disease processes may impair speech understanding with a CI. These disease processes are not yet fully understood. In acoustics, it is known that the auditory brainstem responses (ABR) and their latencies and amplitudes allow differential diagnosis based on reference values for normal-hearing individuals. The aim of this study was to provide reference values for electrically evoked brainstem responses (EABRs) in terms of rate-dependent latencies and amplitudes. Methods: 20 ears of 18 experienced adult CI recipients with a predicted and measured good postoperative word recognition score were recruited from the clinic's patient pool. In the same stimulation mode and intensity we measured latencies and interpeak-latencies of EABRs and electrically evoked compound action potentials (ECAPs). With a defined supra-threshold stimulation intensity above the individual ECAP threshold, we applied stimulation at several rates between 11 and 91 stimuli per second. Results: We found rate dependences for EABR latency t3 and t5 in the order of 0.19 ms and 0.37 ms, respectively, while ECAP was not affected by rate. Correspondingly, the interpeak intervals' rate dependences for t 5 − t 1 , t 5 − t 3 and t 3 − t 1 were of the order of 0.37 ms, 0.18 ms and 0.19 ms. Comparing the EABR amplitudes between the stimulation rates 11/s and 81/s, we found that at 81/s the amplitudes were significantly reduced down: to 73% for A3 and 81% for A5. These rate dependences of latency and amplitude in EABR have characteristics comparable to those of acoustic ABR. Conclusions: These data may serve to provide reference values for EABR and ECAP latencies, interpeak intervals and amplitudes with respect to stimulation rate. Altered response patterns of ECAPs and EABRs to normalised stimulation modes could be used in the future to describe and classify neuropathological processes in a better-differentiated way. [ABSTRACT FROM AUTHOR]