Introduction:
The FMT (Floating Mass Transducer) can be coupled to different parts of the ossicular
chain or the round window membrane (RWM). For placing the FMT in front of the RWM
biological as well as artificial materials have been used to improve the vibratory
transmission into the cochlea. To overcome the undefined contact forces and standardize
the procedure, the Hannover Coupler (HC) has been designed. The new design with a
spring allows a precise and standardized RWM-coupling and exposes a constant and controllable
preload of the FMT to the RWM. Our study shows the first audiological results of the
patients, which have been treated with the improved version of the HC.
Methods:
To assess the audiological outcomes pre- and post- operative hearing thresholds, Freiburg
Monosyllables (FBM) 65 dB and the Oldenburg sentence test in quiet and in noise were
performed up to 6 months. Additionally, questionnaires were performed to compare the
general satisfaction and hearing status.
Results:
Seven patients have been implanted. It could be shown that the inner ear have not
been affected by the surgical invention. The speech perception outcomes in the FBM
were preoperative 0% and after 3 month 80%. Thresholds for speech intelligibility
in quiet were measured with > 72 dB SPL preoperative and < 45 dB SPL after 3 month.
Within the speech in noise test the speech level can be lower than the noise level
(65 dB SPL). This was not possible bevor the implantation.
Conclusion:
The new HC is a reliable and safe method for round window coupling. A precise and
standardized placement of the FMT was possible during the surgical intervention. The
inner ear function has not been affected and preliminary results show good speech
perception outcomes in quiet and noise.
