feedback. Noise picked up through the hearing aid's microphone creates this feedback, which is then amplified creating a ringing noise. Adaptive feedback cancellation cancels the noise with an adaptive filter. The product of the adaptive filter cancels the feedback from the microphone creating clear sound from the hearing aid. Echo Cancellation Echo cancellation is a form of adaptive feedback cancellation used in telephones and teleconferencing devices. Much like adaptive feedback cancellation in hearing aids, echo cancellation uses an adaptive filter to cancel echo reverberations from a microphone. Jammer Suppression Jammer suppression is a way to reject interference with large signals that are much stronger than traditional signals. This process uses an adaptive filter, and its algorithm has applications in all types of signal suppression. Current Research Prediction Error Method Prediction error method is an adaptive feedback cancellation algorithm that focuses on using audio signals instead of speech signals. This change proposes to improve adaptive feedback cancellation in objects like hearing aids and other audio applications. This approach works closely with echo cancellation, and looks to bring the techniques in echo cancellation to hearing aids. Sub-band Feedback Cancellation Sub-band feedback cancellation is a type of adaptive feedback cancellation that relies less on computations and algorithms, but rather uses the signals already in the device to optimize the feedback cancellation. Sub-band feedback cancellations purpose is to make adaptive feedback cancellation cheaper and more widespread. Digital Signal Processing Digital Signal Processing pledges to reduce the effect of adaptive feedback cancellation on sound quality with the use of feedback tests. The method also reports more gain in the hearing aid, and cites a figure of 10 decibels. Adaptive Feedback Cancellation in Smartphones Research from 2018 is ongoing into adaptive feedback cancellation on smartphone speakers and microphones. Current research intends to use digital signal processing to mimic the cancellation in hearing aids in smartphones. References External links Diagram Acoustics