Binaural Integrated Active Noise Control and Noise Reduction in Hearing Aids

International audienceThis paper presents a binaural approach to integrated active noise control and noise reduction in hearing aids and aims at demonstrating that a binaural setup indeed provides significant advantages in terms of the number of noise sources that can be compensated for and in terms of the causality margins

A Weighted Approach for Integrated Active Noise Control and Noise Reduction in Hearing Aids

International audienceThis paper presents a weighted approach for integrated active noise control and noise reduction in hearing aids. An integrated scheme has been introduced previously to tackle secondary path effects and effects of noise leakage through an open fitting. This scheme, however, does not allow to balance between the noise reduction and the active noise control. In some circumstances it will indeed be useful to emphasize one of the functional blocks. A scheme based on a weighted mean squared error criterion is presented here and compared experimentally with the original un-weighted scheme

Output SNR analysis of integrated active noise control and noise reduction in hearing aids under a single speech source scenario

International audienceThis paper analyses the output signal-to-noise ratio for a standard noise reduction scheme and for an integrated active noise control and noise reduction scheme, both applied in the hearing aid framework including the effects of signal leakage through an open fitting and secondary path effects. In particular, a standard noise reduction scheme based on the multichannel Wiener filter and an integrated active noise control and noise reduction scheme based on the filtered-X multichannel Wiener filter are analysed and their signal-to-noise ratio are derived under a single speech source scenario

Assisting the autistic To reduce anxiety caused by their environment

Many people with Autistic Spectrum Disorder (ASD) find certain sounds so unpleasant that their lifestyle can be severely impaired by the need to avoid these noises. This paper considers several common sources of such anxietyinducing noise in the normal home and working environments, and considers whether this problem could be addressed with mechatronic concepts. People with ASD were tested for their reactions to a range of noises, and to the same noises filtered through noise reduction devices. Analysis of the probable characteristics of the anxiety- causing noise features was made. The noises were varying in time and pitch. In addition to anecdotal and survey evidence some carefully structured tests were carried out on some participants using the devices. Based on this investigation, specific mechatronic devices are proposed, using active noise control to selectively soften the sounds, which may be suitably used by those suffering ASD. A smart home or office could deploy multiple devices, in the optimal locations to reduce any offensive noise, whilst preserving a pleasant environment that allows the user the ability to communicate. Furthermore the environment could be tuned to the needs of specific individuals, and switched when they are present

The merit of using silicon for the development of hearing aid microphones and intraocular pressure sensors

An important design rule for a hearing aid is the requirement of a large signal to noise ratio, which is mainly determined by that of the microphone and its preamplifier. It will be shown that in order to increase the signal to noise ratio it is favourable to integrate the preamplifier with the microphone, which implies that the microphone should be made of silicon, preferably with a single wafer technology. For the development of a tonometer for the measurement of intraocular pressure, the application of a silicon force sensor rationalizes that also the flattening of the eye globe is measured with a silicon applanation sensor, instead of by optical means which is the present practice. A sensor construction has been developed, which combines a force, pressure and applanation sensor, all made in silicon

Combined Active Noise Control and noise reduction in Hearing Aids

International audienceThis paper presents a combined active noise control and noise reduction scheme for hearing aids to tackle secondary path effects and effects of signal leakage through the fitting. While such leakage contributions and the secondary accoustic path from the reciever to the tympanic membrane are usually not taken into account in standard noise reduction systems, they appear to have a non-negligible impact on the final signal quality. Integrating an active noise control system in the existing noise reduction algorithm helps to compensate for these effects. A Filtered-x Multichannel Wiener Filter is presented and compared experimentally with a classic Multichannel Wiener Filter in a noise reduction framework

Aerospace Medicine and Biology. A continuing bibliography (Supplement 226)

This bibliography lists 129 reports, articles, and other documents introduced into the NASA scientific and technical information system in November 1981