The Design & Construction of An Audiometer with Built-in Assistive Diagnostics

A low-cost Audiometer was designed and constructed for carrying out primarily, Pure Tone and Speech Audiometry. The Audiometer also included other standard subjective behavioural tests: Tone Decay, SISI (Small Increment Sensitivity Index), ABLB (Alternate Binaural Loudness Balance) Test and Stenger's. Other standard features offered were: output transducer options: Air Conduction Headphones, Bone Vibrator, and Free Field output, Contralateral Masking, Audiogram (during Pure Tone test) on instrument's LCD display, battery operation. In addition to the standard features, the Audiometer introduced two features: One, Assisted Diagnostics. It interpreted the tests conducted on a patient, based on information in the public domain, to point out which part of the auditory system may be malfunctioning (“site of lesion”). The diagnosis was suggestive rather than prescriptive, with the aim of assisting the audiologist or clinician conducting the tests. For example, in a simplest test inference, audiometer classified type of hearing loss: Mild, moderate, severe, profound or total, based on generally accepted criteria. Two, Automatic Calibration to correct for output transducer's acoustic characteristics. It was suggested that this built-in diagnostics could be made more exhaustive and reliable, using Artificial Intelligence tools. Except for PCBs designed by the authors, all components used in the project were standard, low-cost, available in the market.