Microphone Self-Noise (Tympan Rev-D2)

As mentioned in a previous post, it is important for hearing aids that the microphones and electronics have a low self-noise.  Because of the amplification in a hearing aid, what might start as an innocuous amount of noise gets multiplied into a very annoying and fatiguing listening experience.  So, for... [Read More]

Microphone Self-Noise

A hearing assistive device must not be noisy.  At minimum, noise will be annoying.  At worst, noise will harm, not help a person's ability to hear.  So, for our Tympan device, I want to make sure that it has low self-noise.  In this post, I show how the microphone that... [Read More]

Measuring Audio Latency

For real-time audio processing, it is often important to minimize the delay between audio coming out of the system compared to the audio coming into the system.  This is especially true of hearing aids, where too much latency can cause the listener to perceive an echo (or have a comb-filtering... [Read More]

Adding a Real Time Clock to the Tympan

In talking with users of the Tympan, data logging is something that they'd like the Tympan to do.  Furthermore, for the data logging to be useful, the data needs to be time stamped.  So, the Tympan needs to know the time and date.  Normally, one needs to add a dedicated... [Read More]

Calibrating My Earphones with the Tympan

At its core, a hearing aid is a microphone, an amplifier, and an earphone.  Each element is critical to the quality of the sound produced by the device.  For the Tympan, it (currently) is simply the amplifier (ie, the electronics) -- you have to bring your own microphones and speakers.... [Read More]