This article surveys approaches to teleconferencing in voice over IP networks. The considerations for conferencing include perceived quality, scalability, control, and compatibility. Architectures used for conferencing range from centralized bridges to full mesh. Centralized conference bridges used with compressed speech degrade speech quality when multiple talkers are mixed and subjected to ta...

MFCC is widely used together with its delta and delta-delta features in the field of speech recognition based on HMM. MFCC is designed to apply DCT to the MF output. We propose in this paper to employ KL transformation instead of DCT, because it can reflect the statistics of speech data more precisely. MFCC is the compressed feature of the log MF so that some detailed features seem to be lost. ...

Neural networks (NN) are well known for capturing the complex distributions present in data. The ability of the model depends on the structure of the network and the nature of the data used for training [1]. In this paper, we are exploring neural network models for digit recognition in mobile environment. Due to recent advancements and applications in mobile communication, there is a need to de...

Our native language has a lifelong effect on how we perceive speech sounds. Behaviorally, this is manifested as categorical perception, but the neural mechanisms underlying this phenomenon are still unknown. Here, we constructed a computational model of categorical perception, following principles consistent with infant speech learning. A self-organizing network was exposed to a statistical dis...

In Compressed Sensing (CS) framework, reconstruction of a signal relies on the knowledge of the sparse basis & measurement matrix used for sensing. Most of the studies so far focus on the application of CS in fields of images, radar, astronomy and Speech. This paper introduce new approach called combined basis that is made by separating voiced and unvoiced parts and applying different basis for...

In this paper we propose a new speech compression technique based on the application of a psychoacoustic model combined with a general approach for Filter Bank Design using optimization. This technique is a modified version of the compression technique using a MDCT (Modified Discrete Cosine Transform) filter banks of 32 filters each and a psychoacoustic model. The two techniques are evaluated a...

Compressed sensing (CS) is a kind of sampling method based on signal sparse property, it can effectively extract the signal which was contained in the message. In this study, a new noise speech enhancement method was proposed based on CS process. Voice sparsity is used to this algorithm in the discrete fast Fourier transform (Fast Fourier transform, FFT), and observation matrix is designed in c...

The MPEG-1 Layer 3 compression schema of audio signal, commonly known as mp3, has caused a great impact in recent years as it has reached high compression rates while conserving a high sound quality. Music and speech samples compressed at high bitrates are perceptually indistinguishable from the original samples, but very little was known about how compression acoustically affects the voice sig...

The technique of Code Excited Linear Prediction (CELP) has led to the development of voice coding systems that provide toll quality speech at very low bitrates. While speech and singing share many similarities in terms of production, standard speech coding implementations fall far short when transmitting the singing voice. This paper explores the reasons for this discrepancy and suggests new va...

Speech consists of alternating voiced and unvoiced sections. Voiced speech consists of multiple harmonics of some fundamental (F0); unvoiced speech consists of silence, or ltered noise. Here, speech is wideband bandpass ltered into many bands (modelling the cochlea). Each lter output is rectiied (modelling the organ of Corti hair cell action), and bandpass ltered by convolution with the diieren...