| WOLFSON MICROELECTRONICS PLC Patent applications |
| Patent application number | Title | Published |
|---|
| 20100322432 | FREQUENCY CONTROL BASED ON DEVICE PROPERTIES - There is provided a method of controlling a noise cancellation system, the noise cancellation system being for use in a device comprising a speaker for receiving a wanted signal and generating a sound signal therefrom, and the noise cancellation system comprising: a digital filter, for generating a noise cancellation signal from an input signal representative of ambient noise; and an output for applying the noise cancellation signal to the speaker in addition to the wanted signal to generate a sound signal from which the ambient noise has been at least partially cancelled. The method comprises: determining a resonant frequency of the speaker; based on the determined resonant frequency, selecting a set of filter coefficients; and applying the selected set of filter coefficients to the digital filter. | 12-23-2010 |
| 20100195842 | AMBIENT NOISE REDUCTION ARRANGEMENTS - A feedforward ambient noise reduction arrangement ( | 08-05-2010 |
| 20100105447 | AMBIENT NOISE REDUCTION - 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. | 04-29-2010 |
| 20090046867 | Digtal Circuit Arrangements for Ambient Noise-Reduction - The invention provides a digital circuit arrangement for an ambient noise-reduction system affording a higher degree of noise reduction than has hitherto been possible, through the use of a low latency signal processing chain consisting of analogue-to-digital conversion, digital processing and digital-to-analogue conversion. The arrangement converts the analogue signals into N-bit digital signals at sample rate f | 02-19-2009 |
