title: Hearing gain with a BAHA test-band in patients with single-sided deafness.
abstract: OBJECTIVE
  It is assumed that preoperative use of a bone-anchored hearing aid (BAHA) test-band will give a patient lower gain compared to real post-operative gain because of the reduction of energy through the scalp when using a test-band. Hearing gains using a BAHA test-band were analyzed in patients with unilateral hearing loss.
  
  
  METHODS
  Nineteen patients with unilateral sensorineural hearing loss were enrolled. A test-band, which was connected to BAHA Intenso with full-on gain, was put on the mastoid. Conventional air-conduction (AC) pure-tone averages (PTAs) and sound-field PTAs and speech reception thresholds (SRTs) were obtained in conditions A (the better ear naked), B (the better ear plugged), and C (the better ear plugged with a test-band on the poorer mastoid).
  
  
  RESULTS
  Air-conduction PTAs of the poorer and better ears were 91 ± 19 and 18 ± 8 dB HL. Sound-field PTAs in condition B were higher than those in condition A (54 vs. 26 dB HL), which means that earplugs can block the sound grossly up to 54 dB HL through the better ears. The aided PTAs (24 ± 6 dB HL) in condition C were similar to those of the better ears in condition A (26±9 dB HL), though condition C showed higher thresholds at 500 Hz and lower thresholds at 1 and 2kHz when compared to condition A. The hearing thresholds using a test-band were similar to the published results of BAHA users with the volume to most comfortable level (MCL).
  
  
  CONCLUSIONS
  Our findings showed that a BAHA test-band on the poorer ear could transmit sound to the cochlea as much as the better ears can hear. The increased functional gain at 1 and 2kHz reflects the technical characteristics of BAHA processor. The reduction of energy through the scalp when using a test-band seems to be offset by the difference of output by setting the volume to full-on gain and using a high-powered speech processor. Preoperative hearing gains using a test-band with full-on gain seems to be similar to the post-operative gains of BAHA users with the volume to MCL.
authors.affiliation: Department of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Korea.
authors.forename: Do-Youn
authors.initials: DY
authors.lastname: Kim
authors.forename: Tae Su
authors.initials: TS
authors.lastname: Kim
authors.forename: Byoung Soo
authors.initials: BS
authors.lastname: Shim
authors.forename: In Suk
authors.initials: IS
authors.lastname: Jin
authors.forename: Joong Ho
authors.initials: JH
authors.lastname: Ahn
authors.forename: Jong Woo
authors.initials: JW
authors.lastname: Chung
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Yoon
authors.forename: Hong Ju
authors.initials: HJ
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001844:Bone Conduction; D003638:Deafness / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013069:Speech Reception Threshold Test; D053441:Suture Anchors