Importance

Loading Importance Indicators...

Abstract

The invention provides improved ambient noise reduction for ear-worn devices, such as earphones and headphones and for other devices worn upon or used in close proximity to the ear, such as cellular telephone handsets, and it provides, in particular, improvements to “feed-forward” ambient noise-reduction systems. Most feed-forward noise-reduction systems available hitherto purport to operate only below about 1 kHz and, even then, provide only relatively modest amounts of noise reduction. In accordance with this invention, predetermined filter parameters, such as the gain and cut-off frequency of a selected filter stage used in the noise-reduction processing, are mathematically modelled and the model is adjusted in real-time, in response to user-interpretation of a graphical display of a predicted residual noise amplitude spectrum. This allows the user to inspect the predicted residual noise level amplitude spectrum and to iteratively adjust the filter parameters to minimise residual noise in a chosen environment. Instead of being made manually by a user, the iterative adjustments may be automated and implemented under computer control, using known data-fitting methods and/or neural networks.

Loading the Abstract Image...

First Claim