title: Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations.
abstract: Current clinical practice cannot distinguish, with any degree of certainty, the multiple pathologies that produce conductive hearing loss in patients with an intact tympanic membrane and a well-aerated middle ear without exploratory surgery. The lack of an effective non-surgical diagnostic procedure leads to unnecessary surgery and limits the accuracy of information available during pre-surgical consultations with the patient. A non-invasive measurement to determine the pathology responsible for a conductive hearing loss prior to surgery would be of great value. This work investigates the utility of wideband acoustic immittance (WAI), a non-invasive measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for conductive hearing loss. We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n = 8), malleus fixation (n = 10), ossicular disarticulation (n = 10), and superior canal dehiscence (n = 8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of conductive hearing loss.
authors: Harvard-MIT Division of Health Sciences and Technology, Speech and Hearing Bioscience and Technology, Cambridge, MA, United States; Eaton-Peabody Lab, Massachusetts Eye and Ear, Boston, MA, United States. Electronic address: gmerchant@umass.edu.
authors: Gabrielle R
authors: GR
authors: Merchant
authors: Eaton-Peabody Lab, Massachusetts Eye and Ear, Boston, MA, United States; Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.
authors: Saumil N
authors: SN
authors: Merchant
authors: Harvard-MIT Division of Health Sciences and Technology, Speech and Hearing Bioscience and Technology, Cambridge, MA, United States; Eaton-Peabody Lab, Massachusetts Eye and Ear, Boston, MA, United States; Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.
authors: John J
authors: JJ
authors: Rosowski
authors: Harvard-MIT Division of Health Sciences and Technology, Speech and Hearing Bioscience and Technology, Cambridge, MA, United States; Eaton-Peabody Lab, Massachusetts Eye and Ear, Boston, MA, United States; Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.
authors: Hideko Heidi
authors: HH
authors: Nakajima
mesh_terms: D000158:Acoustic Impedance Tests / Q000379:methods*; D000162:Acoustics; D002102:Cadaver; D003198:Computer Simulation; D003937:Diagnosis, Differential; D004429:Ear Ossicles / Q000033:anatomy & histology / Q000473:pathology; D007758:Ear, Inner / Q000473:pathology; D004432:Ear, Middle / Q000033:anatomy & histology* / Q000473:pathology; D006314:Hearing Loss, Conductive / Q000503:physiopathology*; D006801:Humans; D008307:Malleus / Q000033:anatomy & histology / Q000473:pathology; D008953:Models, Anatomic; D009038:Motion; D013056:Spectrophotometry, Ultraviolet; D013701:Temporal Bone / Q000033:anatomy & histology / Q000473:pathology; D014432:Tympanic Membrane / Q000473:pathology
keywords: Conductive hearing loss; Middle-ear; Ossicular disarticulation; Reflectance; Stapes fixation; Superior canal dehiscence; Wideband acoustic immittance