Measuring otoacoustic emissions using Android smartphones (Masterthesis)


Hooman Habibi

27.07.2017, 10:30, room 4981


Otoacoustic emissions (OAEs) are sound signals generated by the cochlea of the inner ear. These emissions can be used to examine the functionality of the inner ear. The first clinical applications of this phenomenon date back to 1980s. Nowadays with prevalence of smart-phones, more and more applications are being migrated to them. The result of this work is an objective hearing test based on OAEs using android platform, which is, to the best of our knowledge, done for the first time. This saves the hardware engineering and manufacturing costs by using the already existing hardware. Additionally, many features of the Android platform in terms of connectivity, data storage and interface are made available with no costs. This work includes an OAE-screener Android App with which Distortion Product OAE is stimulated, recorded and analyzed. The result of each test is expressed in either pass or fail. The required hardware modules for the application are only a typical android device and a hearing probe connected to the audio jack of the device. The developed App uses only the standard Android API and no device-specific drivers. Elaborate tests have been designed and implemented to examine the functionality of the device's audio system and measure the frequency behavior of the audio circuitry of the device in order to correct the input and output levels inside the App in an automatic fashion. In the final section the test results for 1200 single tests on 10 different subjects are presented. The achieved average pass-rate is 80% for Android OAE-screener and 68% for a tested commercial device.