[Suitability of determining percentage hearing loss for monitoring cochlear implant rehabilitation].

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 (pHVKLS) or speech-recognition threshold (pHVFB).

OBJECTIVE

The parameters pHVKLS and pHVFB 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. pHVKLS was calculated from the equal loudness curve 5 CU, pHVFB from the Freiburg speech test in free field.

RESULTS

While pHVKLS shows small variation, the variation in pHVFB is initially larger but decreases over time. Furthermore, starting from initial fitting, the mean pHV shows convergence over time. The difference between pHVFB and pHVKLS is positive and statistically significant.

CONCLUSION

It is possible to calculate pHVKLS and pHVFB from routine data. A correlation of the difference between pHVFB and pHVKLS with successful CI performance seems plausible.