title: Bone conduction hearing sensitivity in normal-hearing subjects: transcutaneous stimulation at BAHA vs BCI position.
abstract: OBJECTIVE
  Bone conduction (BC) stimulation closer to the cochlea has previously been shown to give higher cochlear promontory acceleration measured by laser Doppler vibrometry (LDV). This study is investigating whether stimulation closer to the cochlea also gives improved hearing sensitivity. Furthermore, the study compares shifts in hearing sensitivity (BC thresholds) and ear-canal sound pressure (ECSP).
  
  
  METHODS
  BC hearing thresholds and ECSP have been measured for stimulation at two positions: the existing bone-anchored hearing aid (BAHA) position, and a new bone conduction implant (BCI) position that is located closer to the cochlea.
  
  
  METHODS
  The measurements were made on 20 normal-hearing subjects.
  
  
  RESULTS
  Depending on frequency, the ipsilateral hearing threshold was 3-14 dB better, and the ipsilateral ECSP was 2-12 dB higher for the BCI than for the BAHA position, with no significant differences between threshold and ECSP shifts at group level for most frequencies, and individually only for some subjects.
  
  
  CONCLUSIONS
  It was found that both the objective ECSP and the subjective hearing threshold measurements gave similar improvement as previous LDV measurements for stimulation closer to the cochlea. One exception was that the LDV measurements did not show the improved sensitivity for frequencies below 500 Hz found here.
authors.affiliation: * Department of Signals and Systems, Chalmers University of Technology , Gothenburg , Sweden.
authors.forename: Sabine
authors.initials: S
authors.lastname: Reinfeldt
authors.forename: Bo
authors.initials: B
authors.lastname: Håkansson
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Taghavi
authors.forename: Måns
authors.initials: M
authors.lastname: Eeg-Olofsson
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D001844:Bone Conduction; D003051:Cochlea / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D006320:Hearing Tests / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011312:Pressure; D012016:Reference Values; D014160:Transducers, Pressure; D055815:Young Adult
keywords: Bone conduction; bone conduction implant; bone-anchored hearing aid; ear-canal sound pressure; hearing sensitivity; normal-hearing subjects; objective measure; threshold shift; transcutaneous stimulation