title: Benefit of a new hearing device utilizing cartilage conduction.
abstract: OBJECTIVE
  Our previous study demonstrated that sound was effectively transmitted by attaching a transducer to the aural cartilage even without fixation pressure. This new method for sound transmission was found by Hosoi in 2004, and was termed cartilage conduction (CC). CC can be utilized even in hearing-impaired patients who cannot use air-conduction hearing aids owing to continuous otorrhea or aural atresia. A prototype hearing aid employing CC was investigated in this study.
  
  
  METHODS
  Four patients with conditions such as continuous otorrhea and acquired aural atresia after surgery participated in this study. The CC hearing aid was fitted, and its benefits were assessed by audiometric tests and interview.
  
  
  RESULTS
  Thresholds and speech recognition scores improved in all subjects. However, in subjects with continuous otorrhea, it was difficult to obtain the gains according to the target gains owing to their severe hearing loss and the limitation of the output level. On the other hand, unexpectedly large gains were obtained below 2kHz in the patient with acquired aural atresia. These large gains were probably caused by soft tissue filling the postoperative space. No subjects complained of pain associated with the attachment of the transducer, although such problems are usually observed for a bone-conduction (BC) hearing aid. This feature is considered one of the advantages of the CC hearing aid.
  
  
  CONCLUSIONS
  The results of the audiometric tests and interview suggest that the CC hearing aid has potential as a useful amplification device for hearing disability. Unfortunately, if the soft tissue pathway is not involved, the current device is insufficient for the patients with severe hearing loss. The improvement of the output level will lead to develop a reliable CC hearing aid as an alternative to BC hearing aids or bone anchored hearing aids.
authors: Department of Otolaryngology and Head & Neck Surgery, Nara Medical University, 840 shijo-cho Kashihara, Nara, Japan. t-nishim@naramed-u.ac.jp
authors: Tadashi
authors: T
authors: Nishimura
authors: Hiroshi
authors: H
authors: Hosoi
authors: Osamu
authors: O
authors: Saito
authors: Ryosuke
authors: R
authors: Miyamae
authors: Ryota
authors: R
authors: Shimokura
authors: Toshie
authors: T
authors: Matsui
authors: Takashi
authors: T
authors: Iwakura
mesh_terms: D000328:Adult; D000368:Aged; D001309:Auditory Threshold; D001844:Bone Conduction; D003251:Constriction, Pathologic; D004424:Ear Canal / Q000601:surgery; D004425:Ear Cartilage; D005260:Female; D006310:Hearing Aids; D006314:Hearing Loss, Conductive / Q000150:complications / Q000534:rehabilitation*; D046089:Hearing Loss, Mixed Conductive-Sensorineural / Q000150:complications / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D010035:Otitis Media, Suppurative / Q000150:complications; D013067:Speech Perception; D013069:Speech Reception Threshold Test