Linear predictive coding

About: Linear predictive coding is a research topic. Over the lifetime, 6565 publications have been published within this topic receiving 142991 citations. The topic is also known as: Linear predictive coding, LPC.

Improving sub-band coding of speech at low bit rates by adding residual speech energy signals to sub-bands

Abstract: A sub-band speech coding arrangement divides the speech spectrum into sub-bands and allocates bits to encode the time frame interval samples of each sub-band responsive to the speech energies of the sub-bands. The sub-band samples are quantized according to the sub-band energy bit allocation and the time frame quantized samples and speech energy signals are coded. A signal representative of the residual difference between the each time frame interval speech sample of the sub-band and the corresponding quantized speech sample of the sub-band is generated. The quality of the sub-band coded signal is improved by selecting the sub-bands with the largest residual differences, producing a vector signal from the sequence of residual difference signals of each selected sub-band, and matching the sub-band vector signal to one of a set of stored Gaussian codebook entries to generate a reduced bit code for the selected vector signal. The coded time frame interval quantized signals, speech energy signals and reduced bit codes for the selected residual differences are combined to form a multiplexed stream for the speech pattern of the time frame interval.

Low-delay code-excited linear-predictive coding of wideband speech at 32 kbps

Abstract: The authors report on the use of the codebook-excited linear-predictive (CELP) algorithm for 32 kb/s low-delay (LD-CELP) coding of wideband speech. The main problem associated with wideband coding, namely, spectral noise weighting, is discussed. The authors propose an enhanced noise weighting technique and demonstrate its efficiency via subjective listening tests. In these tests, involving 20 listeners and 8 test sentences, the average rating for the proposed 32 kb/s LD-CELP was essentially equal to that of the 65 kb/s standard (G.722) CCITT wideband coder. >

Speech dereverberation and denoising using complex ratio masks

Abstract: Traditional speech separation systems enhance the magnitude response of noisy speech. Recent studies, however, have shown that perceptual speech quality is significantly improved when magnitude and phase are both enhanced. These studies, however, have not determined if phase enhancement is beneficial in environments that contain reverberation as well as noise. In this paper, we present an approach that jointly enhances the magnitude and phase of reverberant and noisy speech. We use a deep neural network to estimate the real and imaginary components of the complex ideal ratio mask (cIRM), which results in clean and anechoic speech when applied to a reverberant-noisy mixture. Our results show that phase is important for dereverberation, and that complex ratio masking outperforms related methods.

Predictive coding for efficient host-device communication in a pneumatic force-feedback display

Abstract: We investigate predictive coding for reducing the amount of data communicated between a haptic controller and a host. This allows increased update rate, which potentially improves quality even if coding is lossy. A low-order predictive coding is investigated for a pneumatic force display. Due to human and device characteristics, some compression is possible without loss, although the technique is lossy in general. Lossy uniform and nonuniform quantizers are also investigated. An experiment was conducted to determine how much data reduction is possible before compression artifacts become detectable to users.