noise reduction and two band digital crossover

... noise reduction in hearing aids,” IEEE Transactions on Signal Processing, vol 53, no 3, pp 911–925, 2005 8 [10] A K N´ bˇ lek and D Mason, “Effect of noise and reverberaa e tion on binaural and ... postfilters for noise and acoustic echo reduction, ” in Microphone Arrays, M S Brandstein and D B Ward, Eds., chapter 12, pp 255–279, Springer, Berlin, Germany, 2001 [16] T Wittkop and V Hohmann, ... of late reverberant speech and noise yields a significantly better speech quality, in terms of a lower LSD and MBSD as well as a higher SSIR, in comparison to the noise reduction without dereverberation...

Ngày tải lên: 21/06/2014, 22:20

... frequencies and bandwidths are taken according to criticalband spacing These 21-bands cover a frequency range of to 7.7 KHz Energies of each of the 21-filter outputs are computed and normalized ... Upper-edge frequencies, lower-edge frequencies, center frequencies, and bandwidths for 21-channel filter-bank with critical -band spacing Band 10 11 12 13 14 15 16 17 18 19 20 21 Lower-edge frequency ... perceptual analysis of voice pathology These 21 bands cover the frequency range from to 7.7 KHz The bandwidths at lower critical-bands are narrower and they progressively increase as the center...

Ngày tải lên: 22/06/2014, 23:20

... employed to denoise PD signals A global threshold that based on standard deviation is used to remove noise components in all frequency bands However, noise components at various frequency bands can ... SF6 1.2 REVIEW OF NOISE REDUCTION AND DISCRIMINATION In this section, previous works on reduction of white noise and discrimination of corona are reviewed 1.2.1 Removal of White Noise Firstly, methods ... Necessity of Noise Reduction and Discrimination 16 1.1.7 The Necessity of PD Source Recognition 18 1.2 REVIEW OF NOISE REDUCTION AND DISCRIMINATION 20 1.2.1 Removal of White Noise ...

Ngày tải lên: 16/09/2015, 08:30

... Hz to 80 Hz; band is band- pass and covers 80 Hz to kHz; band is high-pass and covers above kHz; and band is also high-pass and covers above kHz At the encoder the gain of each band is adaptively ... each band if the signal level falls 45 dB below the maximum recording level The Dolby B and Dolby C systems are designed for consumer audio systems, and use two bands instead of the four bands ... delay, and can be adjusted to coherently combine the signals The magnitude frequency response of each filter can be used to remove the out–of band noise 1.3.8 Dolby Noise Reduction Dolby noise reduction...

Ngày tải lên: 25/01/2014, 13:20

... detection and removal of impulsive noise and transient noise pulses In Chapter 12, impulsive noise is modelled as a binary−state non-stationary process and several stochastic models for impulsive noise ... .27 CHAPTER NOISE AND DISTORTION 29 2.1 Introduction 30 2.2 White Noise 31 2.3 Coloured Noise 33 2.4 Impulsive Noise .34 2.5 Transient Noise Pulses ... Signals in Noise .167 5.6 Signal and Noise Model Combination and Decomposition .170 5.6.1 Hidden Markov Model Combination 170 5.6.2 Decomposition of State Sequences of Signal and Noise. 171...

Ngày tải lên: 25/01/2014, 13:20

... Hz to 80 Hz; band is band- pass and covers 80 Hz to kHz; band is high-pass and covers above kHz; and band is also high-pass and covers above kHz At the encoder the gain of each band is adaptively ... each band if the signal level falls 45 dB below the maximum recording level The Dolby B and Dolby C systems are designed for consumer audio systems, and use two bands instead of the four bands ... White noise: purely random noise that has a flat power spectrum White noise theoretically contains all frequencies in equal intensity (c) Band- limited white noise: a noise with a flat spectrum and...

Ngày tải lên: 18/04/2014, 13:26

... BEAMformer Digital Noise Reduction System,” Cochlear Clinical Bulletin, April, 1997 A Spriet, L Van Deun, K Eftaxiadis, et al., “Speech understanding in background noise with the two- microphone ... Feuz, J Francois, and J Tinembart, “Multi¸ microphone digital- signal-processing system for research into noise reduction for hearing aids,” Innovation and Technology in Biology and Medicine, vol ... properties of a directional noise reduction system using the proposed supporting algorithms: (a) beam width control using target signal detection algorithms and (b) maximum noise reduction using leakage...

Ngày tải lên: 21/06/2014, 22:20

... Hz to 80 Hz; band is band- pass and covers 80 Hz to kHz; band is high-pass and covers above kHz; and band is also high-pass and covers above kHz At the encoder the gain of each band is adaptively ... each band if the signal level falls 45 dB below the maximum recording level The Dolby B and Dolby C systems are designed for consumer audio systems, and use two bands instead of the four bands ... delay, and can be adjusted to coherently combine the signals The magnitude frequency response of each filter can be used to remove the out–of band noise 1.3.8 Dolby Noise Reduction Dolby noise reduction...

Ngày tải lên: 21/01/2014, 07:20

... A more practical concept is bandlimited white noise, defined as a noise with a flat spectrum in a limited bandwidth The spectrum of band- limited white noise with a bandwidth of B Hz is given by ... shape; examples are pink noise, brown noise and autoregressive noise (e) Impulsive noise: consists of short-duration pulses of random amplitude and random duration (f) Transient noise pulses: consists ... White noise: purely random noise that has a flat power spectrum White noise theoretically contains all frequencies in equal intensity (c) Band- limited white noise: a noise with a flat spectrum and...

Ngày tải lên: 21/01/2014, 07:20

... Autocorrelation and power spectrum of impulsive noise Impulsive noise is a random, binary-state (“on/off”) sequence of impulses of random amplitudes and random time of occurrence In Chapter 12, a random ... stochastic processes for modelling random noise such as white noise, clutters, shot noise and impulsive noise Bibliography ANDERSON O.D (1976) Time Series Analysis and Forecasting The Box– Jenkins ... Model for Clutters and Impulsive Noise An impulsive noise process consists of a sequence of short-duration pulses of random amplitude and random time of occurrence whose shape and duration depends...

Ngày tải lên: 21/01/2014, 07:20

... µx and covariance matrix Σxx, and that the noise n(m) is also Gaussian with mean vector µn and covariance matrix Σnn The signal and noise pdfs model the prior spaces of the signal and the noise ... with a random input e, output x, and parameter vector θ, is a predictive model of the signal x, and n is an additive random noise process In Figure 4.1, the distributions of the random noise n, ... is the random input of the AR model and n is the random noise Using Equation (4.3), the signal restoration process involves the estimation of both the model parameter vector θ and the random input...

Ngày tải lên: 21/01/2014, 07:20

... Speech Wiener filter Noise states Noise Noise HMMs Figure 5.12 Outline configuration of HMM-based noisy speech recognition and enhancement 5.6 Signal and Noise Model Combination and Decomposition ... Wiener filtering and the spectral subtraction methods described in Chapters and 11) or by combining the noise and the signal models to model the noisy Signal and Noise Model Combination and Decomposition ... signal and the noise HMMs maybe expressed as   MAP s signal = arg max  max f Y (Y , ssignal , s noise M ,η )  s signal  s noise (5.46)   MAP s noise = arg max  max f Y (Y , ssignal , s noise...

Ngày tải lên: 21/01/2014, 07:20

... Filter for Additive Noise Reduction Consider a signal x(m) observed in a broadband additive noise n(m)., and model as y(m) = x(m) + n(m) (6.45) Assuming that the signal and the noise are uncorrelated, ... x(m) and the noise n(m): Ryy = Rxx + Rnn (6.46) rxy = rxx (6.47) and we can also write where Ryy, Rxx and Rnn are the autocorrelation matrices of the noisy signal, the noise- free signal and the noise ... separability: (a) The signal and noise spectra not overlap, and the signal can be recovered by a low-pass filter; (b) the signal and noise spectra overlap, and the noise can be reduced but not...

Ngày tải lên: 21/01/2014, 07:20

... m | m − 1) ~ ( m| m − 1)] = x (7.20) and we have also used the assumption that the signal and the noise are uncorrelated Substitution of Equations (7.9) and (7.16) in Equation (7.15) yields the ... y(m)= x(m) + n(m) (7.34) 2 Let σ e (m) and σ n (m) denote the variances of the excitation signal e(m) and the noise n(m) respectively Substituting Φ(m+1,m)=a(m) and H(m)=1 in the Kalman filter equations ... Recursive estimation of a constant signal observed in noise Consider the estimation of a constant signal observed in a random noise The state and observation equations for this problem are given...

Ngày tải lên: 21/01/2014, 07:20

... flexibility and better performance Sub -Band Linear Prediction Model 253 In sub -band linear prediction, the signal x(m) is passed through a bank of N band- pass filters, and is split into N sub -band signals ... of a sub -band linear prediction model Linear Prediction Models 254 where Bk and fk0 are the bandwidth and the centre frequency of the kth subband respectively To ensure that each sub -band LP parameters ... number of subbands and to model the signal within each sub -band with a linear prediction model as shown in Figure 8.12 The advantages of using a sub -band LP model are as follows: (1) Sub -band linear...

Ngày tải lên: 21/01/2014, 07:20

... the two extreme cases of a sine wave and a purely random signal For a periodic signal, the power is concentrated in extremely narrow bands of frequencies, indicating the existence of structure and ... frequencies, such as the bass, without affecting other frequencies, and in subband coding different frequency bands are coded independently and allocated different numbers of bits (ii) Sinusoidal functions ... {vP+1, , vN} span the noise subspace and have σ n as their eigenvalues Since the signal and noise eigenvectors are orthogonal, it follows that the signal subspace and the noise subspace are orthogonal...

Ngày tải lên: 26/01/2014, 07:20

... recognition and decision making systems We started this chapter with a study of the ideal interpolation of a band- limited signal, and its applications in digital- to-analog conversion and in multirate ... original base -band spectrum X(f) and the repetitions or images of X(f) spaced uniformly at frequency intervals of Fs=1/Ts When the sampling frequency is above the Nyquist rate, the baseband spectrum ... case of a band- limited random signal if the sampling rate is greater than M times the Nyquist rate However, in many practical cases, the signal is a realisation of a random process, and the sampling...

Ngày tải lên: 26/01/2014, 07:20

... divided into two parts; a low-frequency band fl and a high-frequency band fh Each point in Figure 11.4 is a plot of the high-frequency spectrum versus the lowfrequency spectrum, in a two- dimensional ... sounding noise, known as “musical tone noise due to their narrowband spectrum and the tin-like sound The success of spectral subtraction depends on the ability of the algorithm to reduce the noise ... effect of noise on a signal in the time and the frequency domains 335 Spectral Subtraction where y(m), x(m) and n(m) are the signal, the additive noise and the noisy signal respectively, and m is...

Ngày tải lên: 26/01/2014, 07:20

... 359 Impulsive Noise 12.1.1 Autocorrelation and Power Spectrum of Impulsive Noise Impulsive noise is a non-stationary, binary-state sequence of impulses with random amplitudes and random positions ... binary-state sequence, and expressed as ni (m) = n(m) b(m) (12.6) where b(m) is a binary-state random sequence of ones and zeros, and n(m) is a random noise process Assuming that impulsive noise is an uncorrelated ... Impulsive Noise 12.1 Impulsive Noise In this section, first the mathematical concepts of an analog and a digital impulse are introduced, and then the various forms of real impulsive noise in communication...

Ngày tải lên: 26/01/2014, 07:20

... of the input and the noise pulse template, and a time delay that can be used to align the input noise and the noise template This information can be used for subtraction of the noise pulse from ... absence of a noise pulse, and provides additional information on the timing and the underlying the states of the noise pulse 13.4.1 Adaptive Subtraction of Noise Pulses The transient noise removal ... transient noise pulses, using the noise template model within a matched filter, the linear predictive model of noise, and the hidden Markov model described in Section 13.2 13.3.1 Matched Filter for Noise...

Ngày tải lên: 26/01/2014, 07:20