An Audio Signal Processor analyze sound signals, process them and explore the signal properties. This paper is a part of the work carried out by the authors for designing the Audio Processor in MATLAB software providing basic functions to read, play and write the sound signal along with signal processing toolbox, which includes numerous functions that work on signals. A unique feature of the pa...

Parametric modelling provides an efficient representation of general audio signals and is utilised in very low bit rate audio coding. It is based on the decomposition of an audio signal into components which are described by appropriate source models and represented by model parameters. Perception models are utilised in signal decomposition and model parameter coding. This paper gives a brief t...

Audio noise reduction system is the system that is used to remove the noise from the audio signals. Audio noise reduction systems can be divided into two basic approaches. The first approach is the complementary type which involves compressing the audio signal in some well-defined manner before it is recorded (primarily on tape). On playback, the subsequent complementary expansion of the audio ...

| This paper presents an audio coding system which uses lter banks to decompose, in the frequency domain, the audio signal into constant width subbands. A speciic compression is applied in each subband. This compression is achieved by means of CELP coders. In order to obtain a high audio quality, psychoacoustic models allocate dynamically the number of bits needed in each sub-band. A particular...

In present stereo audio system is a most popular audio system for different purposes. Now a day’s stereo system is commonly used in communication and other purposes. Moreover Normalized Least Mean Square (NLMS) based adaptive filtering is an effective filtering process in case of communication and other applications. However adaptive filtering is an adaptive filter process to cancel out the noi...

In this paper, we propose a new approach for optimization in digital audio watermarking using artificial intelligent technique. The watermarks are embedded into the low frequency coefficients in discrete multiwavelet transform domain. The embedding technique is based on quantization process which does not require the original audio signal in the watermark extraction. We have developed an optimi...

This paper presents a classification scheme for audio signals using high-level feature descriptors. The descriptor is designed to capture the relevance of each acoustic feature group (or feature set like mel-frequency cepstral coefficients, perceptual features etc.) in recognizing an audio class. For this, a bank of RVM classifiers are modeled for each ‘audio class’-‘feature group’ pair. The re...

The MPEG-4 Audio Standard combines tools for efficient and flexible coding of audio. For very low bitrate applications, tools based on a parametric signal representation are utilised. The parametric speech coding tools (HVXC) are already available in Version 1 of MPEG-4. The main focus of this paper is on the parametric audio coding tools “Harmonic and Individual Lines plus Noise” (HILN) which ...