Acoustic reflectometry: Spectral analysis and the conductive hearing loss of otitis media

Objective. To test the hypothesis that the quality of sound reflected from the tympanic membrane with acoustic reflectometry is predictive of hearing loss caused by otitis media. Methods. A pediatrician in solo primary care practice examined 257 patients for middle ear disease using clinical criteria, tympanometry and an acoustic reflectometer with a recording device. Each ear was diagnosed as normal, acute otitis media or otitis media with effusion. Hearing testing with a select picture audiometer was performed by a technician who was blinded to the diagnosis, Paired data were obtained on some ears. Results. A spectrum of <95 degrees identified 100% of the ears hearing at 30 dB or more because of otitis media, Paired data were obtained on 99 ears with otitis media that failed audiometry on the initial visit. On return 96 of the 99 showed a broader spectrum of reflected sound with improved hearing and clinical improvement of otitis media. Conclusions. Measurement of the width of the spectrum of reflected sound is the basis for a new technology that shows initial promise for being able to provide objective information about the probability of conductive hearing loss caused by otitis media.