NASA Scientific and Technical Aerospace Reports

parameters and propose some important variables to control in musical sound.
Author
Fast Fourier Transformations; Decay; Spectral Energy Distribution; Stiffness
20060001624 Tokyo Inst. of Tech., Yokahama, Japan
High Resolution Frequency Analysis of Voices-Feature Extraction of Nasal Consonants
Harada, Tetsuya; Kawarda, Hiroshi; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP
‘87); Volume 1; 1987, pp. 8.7.1 - 8.7.4; In English; See also 20060001583; Copyright; Avail.: Other Sources
This paper gives a high resolution spectral analysis of Japanese nasal syllables uttered by 50 male and female speakers,
feature extraction and recognition experiments. The spectral analyzer consists of a band-pass filter bank whose resolution is
24 or 96 channels per octave and Q=30 or 14. Detailed observation of spectral patterns of the nasal syllables shows that the
features which distinguish between labial and alveolar exist not only in the second formant transition but also in frequency
interval between the second and higher formants. In the recognition experiments for 1,000 nasal syllables based on a new
recognition method named augmented feature space method (AFSM), all syllables are recognized correctly excluding several
misheard ones in the hearing test.
Author
Frequencies; Speech Recognition; Spectrum Analysis
20060001635 Analysis and Technology, Inc., North Stonington, CT, USA
Design of Continuous Gain Adaptive Alpha Beta Trackers for Passive Sonar Application
Wenk, Carl J.; Jarvis, Harold F., Jr.; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP
‘87); Volume 1; 1987, pp. 12.1.1-12.1.4; In English; See also 20060001583; Copyright; Avail.: Other Sources
This paper presents a new method for realtime tracking of target signal parameters in passive underwater acoustics. The
method provides a recursive, closed-loop alpha beta tracking algorithm, in which gains alpha and beta adapt automatically in
a continuous-valued, instantaneous manner, to both received target signal-to-noise ratio variation, and target dynamical
maneuvers.
Author
Underwater Acoustics; Amplification; Adaptive Control; Tracking (Position)
20060001637 Naval Underwater Systems Center, New London, CT, USA
High Resolution Multipath Time Delay Estimation for Broadband Random Signals
Ianniello, John P.; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP ‘87); Volume 1;
1987, pp. 12.4.1 - 12.4.4; In English; See also 20060001583; Copyright; Avail.: Other Sources
We examine the limits to multipath time delay resolution for broadband random signals. We first derive Cramer-Rao
bounds for both two path and three path cases to establish baseline performance for unbiased estimation. We then compare
the bounds with computer simulation. For the two path case we implement a maximum likelihood estimator while for the three
path case we estimate the delays using the Modified Forward Backward Linear Prediction algorithm developed for high
resolution frequency estimation. It is shown that both techniques achieve performance close to the Cramer-Rao bound.
Author
Broadband; High Resolution; Random Signals; Time Lag; Mathematical Models
20060001638 Naval Underwater Systems Center, New London, CT, USA
A Practical Approach to Estimation of Amplitude Time Delay Parameters of a Composite Signal in Non-White
Gaussian Noise
Tremblay, Roger J.; Carter, G. Clifford; Lytle, Dean W.; IEEE International Conference on Acoustics, Speech, and Signal
Processing (ICASSP ‘87); Volume 1; 1987, pp. 12.9.1 - 12.9.4; In English; See also 20060001583; Copyright; Avail.:
Other Sources
A method for estimating the amplitude and time delay parameters for signals which can be represented as a sum of a
number of scaled and delayed replicas of a known signal in the presence of non-white Gaussian noise is presented. The method
is based upon the principles of maximum likelihood estimation but at certain key points simplifying assumptions are made
that result in a computationally practical estimation scheme.
Author
Delay; Time Lag; Signal Analysis; Maximum Likelihood Estimates
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