Phase III results with a totally implantable piezoelectric middle ear implant: speech audiometry, spatial hearing and psychosocial adjustment.
OBJECTIVE
To evaluate the treatment efficacy of an electromechanical middle ear amplifier implant (AI) in patients with chronic moderate-to-severe sensorineural hearing loss (SNHL). The AI is a piezoelectric system with a sound processor and a rechargeable battery within a hermetically sealed titanium canister. Its titanium-sealed microphone is placed in the bony region of the ear canal. The incus-coupled transducer (actuator), which is also inside a titanium casing, is fastened to the adjacent bone.


METHODS
This was a phase III study comprising 20 intention-to-treat patients. Telemetrical adjustments followed electromechanical amplifier implantations. We used a word recognition test as our primary efficacy measure (Freiburg Speech Recognition Test: DIN 45621). Secondary efficacy measures were the sentence comprehension test (Goettinger Satztest, 1996) for auditory orientation within noisy and quiet environments and a psychosocial adjustment test (Gothenburg Profile Test, 1998). The 6-month follow-up comprised a complete medical examination. Nineteen patients completed the study (per-protocol patients; 100% reference).


RESULTS
Seventeen patients (89%) demonstrated improved binaural recognition of phonetically balanced monosyllables. Fourteen postoperative patients (74%) attained a perfect score (100%) on this test, compared to only 3 preoperative patients (16%). Thirteen patients (68%) reached the sentence recognition threshold at a 2:1 dB signal-to-noise ratio during noisy trials. Correct identification of the noise source direction in the horizontal plane occurred in 89% of the trials. The Gothenburg Profile Test scores showed that the subjective evaluation of hearing, orientation, social behavior and self-confidence increased from 48% to 88%. Three patients did not benefit from the implant.


CONCLUSIONS
Treatment of SNHL with a totally implantable hearing system can be an efficient method for those patients unable to wear hearing aids. However, in order to avoid implantation in non-responders, there is a need for more specific audiological indication criteria.
Zenner
H Peter
HP
Department of Otolaryngology, University of Tübingen, Germany. zenner@uni-tuebingen.de
Limberger
Annette
A
Baumann
Joachim W
JW
Reischl
Gabriele
G
Zalaman
Ilse M
IM
Mauz
Paul S
PS
Sweetow
Robert W
RW
Plinkert
Peter K
PK
Zimmermann
Rainer
R
Baumann
Ingo
I
De Maddalena
Harry
H
Leysieffer
Hans
H
Maassen
Marcus M
MM
D001301:Audiometry, Pure-Tone; D001302:Audiometry, Speech; D001309:Auditory Threshold; D005069:Evaluation Studies as Topic; D005260:Female; D006312:Hearing Loss, Bilateral / Q000628:therapy*; D006319:Hearing Loss, Sensorineural / Q000628:therapy*; D006801:Humans; D008297:Male; D009998:Ossicular Prosthesis; D018579:Patient Selection; D011446:Prospective Studies; D011474:Prosthesis Design; D012917:Social Adjustment; D013067:Speech Perception; D016896:Treatment Outcome