Abstract: In embodiments of this invention howling sounds are removed without disturbing speech and music. Microphone signals are converted to the frequency domain where howling frequencies are detected and estimated using howling to noise ratios. A notch filter adaptively designed for the howling frequency is applied to remove the howling.

Abstract: A universal reconfigurable system and method are provided for reducing nonlinear echo and residual echo, and for echo leakage prevention in various time-varying and complex environments is proposed in this invention. According to one embodiment an echo cancellation system includes (1) an adaptive linear filter implemented in either time-domain or frequency-domain; (2) a nonlinear echo suppression; (3) echo leakage prevention; (4) direct current (DC), low frequency residual echo and noise reduction; (5) time-domain nonlinear processor (NLP) to reduce the residual echo; and (6) frequency-domain NLP to further reduce the residual echo. The echo cancellation system is universally applicable to acoustic echo cancellation (AEC) and/or electrical echo cancellation applications. In terms of AEC, this invention is reconfigurable for one or more microphones and/or one or more reference channels. The numbers of microphones and reference channels are user configurable.

Abstract: In embodiments of this invention howling sounds are removed without disturbing speech and music. Microphone signals are converted to the frequency domain where howling frequencies are detected and estimated using howling to noise ratios. A notch filter adaptively designed for the howling frequency is applied to remove the howling.

Abstract: A universal reconfigurable system and method are provided for reducing nonlinear echo and residual echo, and for echo leakage prevention in various time-varying and complex environments is proposed in this invention. According to one embodiment an echo cancellation system includes (1) an adaptive linear filter implemented in either time-domain or frequency-domain; (2) a nonlinear echo suppression; (3) echo leakage prevention; (4) direct current (DC), low frequency residual echo and noise reduction; (5) time-domain nonlinear processor (NLP) to reduce the residual echo; and (6) frequency-domain NLP to further reduce the residual echo. The echo cancellation system is universally applicable to acoustic echo cancellation (AEC) and/or electrical echo cancellation applications. In terms of AEC, this invention is reconfigurable for one or more microphones and/or one or more reference channels. The numbers of microphones and reference channels are user configurable.

Abstract: The present invention relates to nanostructured composites comprising a nanotube network which is at least partially embedded within a carbon layer. The present invention particularly relates to conducting nanostructured composites for use in the fields of energy conversion, energy storage and also the biomedical field. The present invention also relates to a process via CVD of carbon onto a catalyst layer on a substrate. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Abstract: The present invention relates to nanostructured composites, in particular nanotube/substrate composites for use in the fields of biomedical materials and devices as well as energy conversion and storage, ion transport and liquid and gas separation. The use of such composites as biomaterials are of particular interest.