Performing tympanometry using smartphones

Plain language summaryTympanometry is a test used to evaluate the health of the middle ear, which is involved in hearing, and helps in diagnosing middle ear disorders. However, the test currently requires expensive equipment and is limited in availability in resource-constrained settings. We present a low-cost smartphone-based tympanometry system. The device is able to change the air pressure of the ear canal and measure ear drum mobility. Our system, for which the software and hardware are openly available, is tested in 50 ears from children attending an audiology clinic. A panel of pediatric audiologists classified tympanometry measurements from our device and a commercial tympanometer with good agreement. Given the increasing availability of smartphones in developing countries, our system has the potential to make screening of middle ear disorders more accessible. BackgroundTympanometry is used as part of a battery of tests for screening of middle ear function and may help diagnose middle ear disorders, but remains available only on expensive test equipment.MethodsWe report a low-cost smartphone-based tympanometer system that consists of a lightweight and portable attachment to vary air pressure in the ear and measure middle ear function. The smartphone displays a tympanogram and reports peak acoustic admittance in realtime. Our programmable and open-source system operates at 226 Hz and was tested on 50 pediatric patient ears in an audiology clinic in parallel with a commercial tympanometer.ResultsOur study shows an average agreement of 86 & PLUSMN; 2% between the 100 tympanograms produced by the smartphone and commercial device when five pediatric audiologists classified them into five classes based on the Liden and Jerger classification.ConclusionGiven the accessibility and prevalence of budget smartphones in developing countries, our open-source tool may help provide timely and affordable screening of middle ear disorders. Chan et al. develop an open-source smartphone-based tympanometer to evaluate middle ear function. The authors test their device in a group of paediatric patients at an audiology clinic and report a high level of agreement in audiologists' classification of tympanograms produced using this device compared with a commercial device.