3 ms·
> Analog aids merely amplify existing sound—a more sophisticated version of an ear trumpet—such that there is no real interruption of the original acoustic wave
by blattimwind 7y ago
> Analog aids merely amplify existing sound—a more sophisticated version of an ear trumpet—such that there is no real interruption of the original acoustic wave.
That's just false and shows how little the author understands about audio systems. The microphone and driver in a hearing aid (and their interaction with the ear canal) alone will change the sound drastically, regardless of whether the signal processing between the two is analog or digital.
- willis936 7y agoIn fairness the latency of an amplifier with no filtering is less than 10 microseconds. Coherency between the amplified and unamplified signal is preserved. I’ve done some personal work on custom IEMs with ANC and the lowest latency controller I could find was the teensy. Even in the fastest round trip time you would be adding 5-10 ms of latency. Speed of sound / 16 kHz = 2 cm. A whole cycle at 2cm. If you want coherent wavefronts then low latency is essential. If the latency is fixed and less than the distance between the speaker and the eardrum (very short) then you can do some DSP tricks to fix up destructive interference.