Noise

About: Noise is a research topic. Over the lifetime, 5111 publications have been published within this topic receiving 69407 citations. The topic is also known as: Мопсы танцуют под радио бандитов из сталкера 10 часов.

An integrated real-time beamforming and postfiltering system for nonstationary noise environments

Abstract: We present a novel approach for real-time multichannel speech enhancement in environments of nonstationary noise and time-varying acoustical transfer functions (ATFs). The proposed system integrates adaptive beamforming, ATF identification, soft signal detection, and multichannel postfiltering. The noise canceller branch of the beamformer and the ATF identification are adaptively updated online, based on hypothesis test results. The noise canceller is updated only during stationary noise frames, and the ATF identification is carried out only when desired source components have been detected. The hypothesis testing is based on the nonstationarity of the signals and the transient power ratio between the beamformer primary output and its reference noise signals. Following the beamforming and the hypothesis testing, estimates for the signal presence probability and for the noise power spectral density are derived. Subsequently, an optimal spectral gain function that minimizes the mean square error of the log-spectral amplitude (LSA) is applied. Experimental results demonstrate the usefulness of the proposed system in nonstationary noise environments.

Adaptive proportional gain audio mixing system

Abstract: An improved audio mixing system. The system is not limited to one type of microphone and does not depend on separate sensing microphones to determine the background noise level. In addition, the active signal is not amplitude modulated by extraneous noise inputted through inactive microphones. The mixing system divides the system gain between a plurality of input channels. The mixing system periodically samples the channels and determines which channel is the dominant channel. In response to this determination, the gain of the dominant channel is increased and that of the other channels decreased.

Noise suppression apparatus

Abstract: A noise suppression apparatus has a main microphone for mainly picking up a voice and for outputting an input signal including an audio signal and a first noise component generated from a noise source, a reference microphone for picking up a second noise component generated from the noise source, a filter bank for band-dividing the input signal from the main microphone and the second noise component from the reference microphone, and a noise cancel circuit for obtaining a phase difference between the input signal and the second noise component with respect to each divided band of the filter bank so as to correct the input signal based on the phase difference and for cancelling the first noise component in the input signal by use of the corrected input signal.

Method and apparatus for multi-channel active control of noise or vibration or of multi-channel separation of a signal from a noisy environment

Abstract: The present invention is directed to a system and method for feed-forward active control of noise and vibration. In operation, at least one of noise and vibration from potential noise and vibration sources are detected, and noise reference data based on the detection of noise and vibration from the potential noise and vibration sources is generated. Further, at least one of noise and vibration at a selected environment in which noise and vibration are to be minimized are also detected, whereby error data based on the detection of noise and vibrations at the selected environment is generated. Filter constants are generated based on the noise reference data and the error data, wherein the generating of the filter constants includes the elimination of redundancies in the noise reference data. The noise reference data is processed based on the generated filter constants, whereby noise/vibration canceling outputs based on the processed noise reference data is generated to minimize energy of the noise and vibration detected at the selected environment.

Noise level in a pediatric intensive care unit.

Abstract: Objective The purpose of this study was to verify the noise level at a PICU Methods This prospective observational study was performed in a 10 bed PICU at a teaching hospital located in a densely populated district within the city of Sao Paulo, Brazil Sound pressure levels (dBA) were measured 24 hours during a 6-day period Noise recording equipment was placed in the PICU access corridor, nursing station, two open wards with three and five beds, and in isolation rooms The resulting curves were analyzed Results A basal noise level variation between 60 and 70 dBA was identified, with a maximum level of 120 dBA The most significant noise levels were recorded during the day and were produced by the staff Conclusion The basal noise level identified exceeds International Noise Council recommendations Education regarding the effects of noise on human hearing and its relation to stress is the essential basis for the development of a noise reduction program