Hearing loss is a common problem for many, especially those who may have attended too many loud concerts in their youth. [mircemk] had recently taken a hearing test and noticed that the procedure was actually quite simple. With this knowledge, he decided to build his own test system and document it for others to use.
By using an Arduino to produce tones of different stepped frequencies and gradually increasing the volume until the test subject can detect the tone, an audiogram of hearing threshold sensitivity can be plotted. Testing each ear individually allows a comparison between one side and the other.
[mircemk] built a nice miniature cabinet that contains an 8×8 array of WS2812 addressable RGB LEDs. A 128×64 pixel OLED display provides user guidance and a rotary encoder with push button serves as user input.
Of course, this is not professional calibrated test equipment, and a lot will depend on the quality of the earphone used. However, as a way to check for serious hearing problems and as an interesting experiment, it shows great promise.
There is even an extension, including a Class D audio amplifier, which allows the use of bone conduction headphones to help further reduce the cause of hearing loss.