Publications
Peak-to-rms reduction of speech based on a sinusoidal model
Summary
Summary
In a number of applications, a speech waveform is processed using phase dispersion and amplitude compression to reduce its peak-to-rms ratio so as to increase loudness and intelligibility while minimizing perceived distortion. In this paper, a sinusoidal-based analysis/synthesis system is used to apply a radar design solution to the problem...
Short-time signal representation by nonlinear difference equations
Summary
Summary
The solution of a nonlinear difference equation can take on complicated deterministic behavior which appears to be random for certain values of the equation's coefficients. Due to the sensitivities to initial conditions of the output of such "chaotic" systems, it is difficult to duplicate the waveform structure by parameter analysis...
Noise reduction using a soft-decision sine-wave vector quantizer
Summary
Summary
The need for noise reduction arises in speech communication channels, such as ground-to-air transmission and ground-based cellular radio, to improve vocoder quality and speech recognition accuracy. In this paper, noise reduction is performed in the context of a high-quality harmonic serc-phase sine-wave analysis/synthesis system which is characterized by sine-wave amplitudes...
An approach to co-channel talker interference suppression using a sinusoidal model for speech
Summary
Summary
This paper describes a new approach to co-channel talker interference suppression on a sinusoidal representation of speech. The technique fits a sinusoidal model to additive vocalic speech segments such that the least mean-squared error between the model and the summed waveforms is obtained. Enhancement is achieved by synthesizing a waveform...
Far-echo cancellation in the presence of frequency offset (full duplex modem)
Summary
Summary
In this paper, we present a design for a full-duplex echo-cancelling data modem based on a combined adaptive reference algorithm and adaptive channel equalizer. The adaptive reference algorithm has the advantage that interference to the echo canceller caused by the far-end signal can be eliminated by subtracting an estimate of...
Phase coherence in speech reconstruction for enhancement and coding applications
Summary
Summary
It has been shown that an analysis-synthesis system based on a sinusoidal representation leads to synthetic speech that is essentially perceptually indistinguishable from the original. A change in speech quality has been observed, however, when the phase relation of the sine waves is altered. This occurs in practice when sine...
Mixed-phase deconvolution of speech based on a sine-wave model
Summary
Summary
This paper describes a new method of deconvolving the vocal cord excitation and vocal tract system response. The technique relies on a sine-wave representation of the speech waveform and forms the basis of an analysis-synthesis method which yields synthetic speech essentially indistinguishable from the original. Unlike an earlier sinusoidal analysis-synthesis...
Speech transformations based on a sinusoidal representation
Summary
Summary
In this paper a new speech analysis/synthesis technique is presented which provides the basis for a general class of speech transformations including time-scale modification, frequency scaling, and pitch modification. These modifications can be performed with a time-varying change, permitting continuous adjustment of a speaker's fundamental frequency rate of articulation. The...
Speech analysis/synthesis based on a sinusoidal representation
Summary
Summary
A sinusoidal model for the speech waveform is used to develop a new analysis/synthesis technique that is characterized by the amplitudes, frequencies, and phases of the component sine waves. These parameters are estimated from the short-time Fourier transform using a simple peak-picking algorithm. Rapid changes in the highly resolved spectral...
Frequency sampling of the short-time Fourier-transform magnitude for signal reconstruction
Summary
Summary
Unique recovery of a signal from the magnitude (modulus) of the Fourier transform has been of long-standing interest in image and optical processing in which Fourier-transform phase is lost or difficult to measure. We investigate an alternative problem of recovering a signal from the Fourier-transform magnitude of overlapping regions of...