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 optimized high payload audio watermarking algorithm based on LU-factorization

Abstract: In the field of audio watermarking, reliably embedding the large number of watermarking bits per second in an audio signal without affecting the audible quality of the host audio with good robustness against signal processing attacks is still one of the most challenging issues. In this paper, a high payload, perceptually transparent and robust audio watermarking solution for such a problem by optimizing the existing problem using genetic algorithm is presented. The genetic algorithm in this paper is used to find the optimal number of audio samples required for hiding each watermarking bit. The embedding is done using the imperceptible properties of LU (lower upper) factorization in wavelet domain. This paper addresses the robustness within perceptual constraints at high payload rate in both mathematical analysis and experimental testing by representing behavior of various attacks using attack characterization. Experimental results show that the proposed audio watermarking algorithm can achieve 1280 bps capacity at an average Signal-to-noise ratio (SNR) of 31.02 dB with good robustness to various signal processing attacks such as noise addition, filtering, and compression. In addition, the proposed watermarking algorithm is blind as it does not require the original signal or watermark during extraction. The comparison of the proposed algorithm with the existing techniques also shows that the proposed algorithm is able to achieve high payload with good robustness under perceptual constraints.

Natural flicker noise (“1/f noise”) in music

Abstract: A large class of musical selections exhibits a spectral density of audio power fluctuations characterized by a low-frequency behaviour typical of 1/f noise. We show that this 1/f behaviour follows from natural flicker noise theory.

Penalty for impulse noise, derived from annoyance ratings for impulse and road-traffic sounds.

Abstract: In the laboratory, four groups of 16 subjects rated the annoyance caused by three types of impulse sounds (regular and irregular gunfire noise and metal‐construction noise) and by road‐traffic sounds, all presented in background noise. The subjects were presented with the sounds for 5‐min periods. The annoyance ratings were related to the A‐weighted equivalent level (Leq) of the sounds. From these annoyance ratings a correction term or penalty was derived, which, added to the Leq of the impulse sounds, gives the level of equally annoying traffic noise. The correction was determined for conditions in which (1) only the annoyance caused by specific sources, or (2) the annoyance caused by the total sound (specific source plus background) had to be rated. In addition, the indoor Leq of the constantly present background noise was 35 or 55 dB(A) by and large, the results showed that for lower levels of the sounds an impulse‐noise correction of at least 10 dB was required, whereas for higher levels the derived c...

Floor impact noise suppressor in a multi-storied building

Abstract: A noise suppressor for reducing propagation of a floor impact noise generated in an upper story to a lower story in a multi-storied building is disclosed. A reference sensor set at a position between a floor of the upper story and a ceiling of the lower story detects a floor impact noise generated in the upper story and converts the noise to an electric signal. This signal is computed and processed by a control unit and transmitted to a speaker located at a position lower than the reference sensor. The speaker emitts a sound wave interfering the floor impact noise to eliminate the noise. The noise not having been suppressed is detected by an error sensor and processed together with the noise detected by the reference sensor by the control unit, thus a sound wave to be emitted from the speaker is corrected appropriately.

Apparatus for recording and/or reproducing video and audio signals

Abstract: For providing high-quality reproduction of audio in a video tape recorder (VTR), the video and audio signals are recorded as first and second mixed signals in successive alternately arranged adjacent first and second parallel record tracks, respectively, extending obliquely on a magnetic record tape, with the first and second mixed signals being comprised of respective carriers of different frequencies which are modulated by an audio signal to constitute respective FM audio signals mixed with a video signal. In a normal reproducing mode of the VTR, in which the tape is advanced at a normal speed corresponding to that used for recording, magnetic heads scan substantially along the adjacent first and second record tracks in succession for alternately reproducing the first and second mixed signals therefrom, the FM audio signals are separated from the reproduced mixed signals and then are demodulated for obtaining therefrom respective alternately reproduced portions of the audio signal, and the alternately reproduced portions are sequentially combined to reconstitute the audio signal therefrom. In another reproducing mode in which the tape is advanced at other than its normal speed, the heads scan imperfectly along the record tracks so that the mixed signals are reproduced therefrom with noise particularly when the heads are situated adjacent end portions of the tracks being imperfectly scanned, and a noise compensating circuit is operative, in that other reproducing mode, for removing the noise from the reconstituted audio signal.