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.

Comfort noise including recorded noise

Abstract: A short period of background noise is recorded (10) during a call and then played back during non-speech intervals, thereby matching as nearly as possible the spectrum and amplitude of actual background noise during the call. Segments of the recording are played back in random order to mask repetition. Recording can take place more than once during a single call or take place in more than one session. In accordance with another aspect of the invention, a small amount of white noise (33) is added to the recorded noise to improve randomness of the sound.

Impulse noise reducer detecting impulse noise from an audio signal

Abstract: An impulse noise reducer detects impulse noise in an audio signal by detecting and smoothing the high-frequency amplitude of the audio signal, attenuating the non-smoothed amplitude according to the smoothed amplitude, and comparing the attenuated amplitude with a threshold. Impulse noise is discriminated from high-frequency audio components because the latter tend to occur in longer-lasting bursts and are therefore attenuated more strongly. The impulse noise reducer is simplified because it does not have to perform intermediate-frequency signal processing, and its sensitivity is not affected by adjacent-channel signals because these signals are substantially absent from the audio signal. The impulse noise reducer can be implemented by digital signal processing, and is suitable for use in a medium-wave AM audio broadcast receiver.

Time-scale modification of audio signals with combined harmonic and wavelet representations

Abstract: We propose a new time-scale modification method for high quality audio signals. Our approach strives to preserve pitch and timbre. In our method, the signal is represented as the sum of sinusoidal components and a residual (edges and noise). The decomposition is computed via a combined harmonic and wavelet representation. Time-scaling is performed on the harmonic components and residual components separately. The harmonic portion is time-scaled by demodulating each harmonic component to DC, interpolating and decimating the DC signal, and remodulating each component back to its original frequency. The residual portion is time-scaled by preserving edges and relative distances between the edges while time-scaling the stationary (noise) components between the edges.

Sound effect switching method and system for mobile terminal

Abstract: The invention discloses a sound effect switching method and system for a mobile terminal. The method comprises the steps that the stream label of an output scene of an audio stream is defined and serves as a mark for distinguishing output scene types, the matching relations between output scene types and the sound modes supported by the mobile terminal are established, and a sound effect comparison table is formed; when an audio output instruction is detected, an audio management service of the mobile terminal identifies the output scene type of the current audio stream by reading the stream label; the sound mode is switched to be matched with the output scene of the audio stream according to the sound mode comparison table. According to the sound effect switching method and system for the mobile terminal, the output scene of the audio stream is identified by means of the audio management service, the matched sound mode is obtained through automatic switching under different scenes, the problem that due to the fact that the global sound effect is not applicable to certain scenes, noise is caused or expected audio enjoyment can not be reached is solved, it is guaranteed that suitable sound effects can be obtained under different application scenes, manual switching conducted by users is not needed, and experience is improved.

The effects of subtractive-type speech enhancement/noise reduction algorithms on parameter estimation for improved recognition and coding in high noise environments

Abstract: The authors present the results of a study designed to investigate the effects of subtractive-type noise reduction algorithms on LPC-based spectral parameter estimation as related to the performance of speech processors operating with input SNRs of 15 dB and below. Subtractive noise preprocessing greatly improves the SNR, but system performance improvement is not commensurate. LPC spectral estimation is affected by the character of the residual noise which exhibits greater variance and spectral granularity than the original broadband noise. The study shows that removing less than the full amount of noise and whitening it improves spectral estimation and speech device performance. Techniques and performance results are presented. >