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Heat and mass transfer of porous plate boundary layer reaction with ethyl alcohol in low speed wind tunnel
Topics: SPEECH RECOGNITION, VOCODERS, VOICE DATA PROCESSING, BANDPASS FILTERS, COMMAND AND CONTROL,...
To help achieve universal secure communications interoperability in the Department of Defense (DoD), one intermediate goal has been the development of a universal voice encoder (vocoder) that can seamlessly encode speech at a wide range of variable and fixed data rates to suit a wide range of DoD communication equipment. This report describes the most recent advancements in achieving this goal. Four of the most important areas of improvements presented are: (1) Significant improvements were...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *DATA RATE, *VARIABLES, *VOCODERS, CODING, SECURE...
This report documents the design and implementation of a Voice Response System (VRS) using Adaptive Differential Pulse Code Modulation (ADPCM) voice coding. Implemented on a Digital Equipment Corporation PDP-11/20, this VRS system supports a single audio output channel. Vocabulary size is limited to 900 words or phrases. Input to the system consists of text messages or sentences in ASCII format transmitted to the 11/20 through a 300-baud asynchronous interface. A preliminary design for a VRS...
Topics: DTIC Archive, INPUT OUTPUT COMPUTER SERVICES INC CAMBRIDGE MASS, *VOICE COMMUNICATIONS, *VOCODERS,...
The report presents the results of a survey in which the Diagnostic Rhyme Test was used to evaluate the present state of digital technique for speech processing and communication. Also presented are the results of a series of minor studies concerned with the methodology of intelligibility evaluation.
Topics: DTIC Archive, Voiers, William D, TRACOR INC AUSTIN TX, *VOCODERS, DIGITAL SYSTEMS,...
The report contains an assessment of CV-3333/U Vocoder reliability performance observed on 22 platforms from approximately June 1978 thru March of 1979. 2 failures occurred during a reported 47,677 operating hours. The point estimate MTBF is 23,838 hours. (Author)
Topics: DTIC Archive, NAVAL WEAPONS SUPPORT CENTER CRANE IN, *RELIABILITY, *VOCODERS, OPERATIONAL...
Research into and the development of instrumentation for the investigation of factors affecting the quality of vocoded speech are documented. The work reported was specifically concerned with developing a better understanding of the role of the vocal source in the production of both synthetic speech and of natural speech. The design of and operating instructions for the VOTIF vocal track inverse filter - built as part of the program - are presented. A theoretical determination of the...
Topics: DTIC Archive, Crystal, Thomas H, SIGNATRON INC LEXINGTON MA, *SPEECH, *VOCODERS, INTERACTIONS,...
This report describes our work in the past three years on data compression and quality evaluation of digital speech. We developed and implemented linear predictive coding (LPC) techniques with the overall objective of digitally transmitting high quality speech at the lowest possible average data rates over packet-switched communication media. Major techniques reported include: covariance lattice method of linear prediction analysis, adaptive lattice methods, linear predictive spectral warping,...
Topics: DTIC Archive, Viswanathan, R, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH COMPRESSION,...
ARINC Research Corporation has completed Phase I of the Microelectronic Transceiver Development Program, performed under Contract N00123-68-C-2520 for the U.S. Navy Electronics Laboratory Center, San Diego, California. This effort was conducted under the technical direction of Code S-240, and consisted of the following tasks; (a) A complete evaluation of the equipment, materials, procedures, and general capability of the NELC Hybrid Microelectronics Laboratory; (b) Expansion of this capability...
Topics: DTIC Archive, Rosenberg,H, ARINC RESEARCH CORP SANTA ANA CALIF WESTERN DIV, *MICROELECTRONICS,...
Much research has been conducted on the discrimination of pure and complex tones. Yet relatively little work has been carried out on the discrimination of pitch in speech. Thus, the present experiment was designed to explore listener's ability to discriminate the pitch to three types of acoustically complex stimuli - pulse trains with monotone pitch, vocoded speech with monotone pitch, and vocoded speech with natural pitch. Results revealed that the discrimination of naturally intoned sentences...
Topics: DTIC Archive, Mack, M. A., MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH,...
The experiment reported in the present study was designed to compare the intelligibility of natural and LPC-vocoded linguistic stimuli presented to native and non-native speakers (listeners) of English. Subjects were 20 native speakers of English and 20 native speakers of German who were fluent in English. Three types of stimuli-the Diagnostic Rhyme Test, the Meaningful Sentences Test, and the Semantically Anomalous Sentences Test-were presented in both natural and vocoded conditions. Results...
Topics: DTIC Archive, Mack, M, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH RECOGNITION,...
The aim of this thesis work is to explore the use of fuzzy systems in a speech coding and classification application. A mixed excitation LPC based speech coder is developed. The excitation classifier for the speech coder is then implemented using a fuzzy system. The fuzzy logic based classifier determines the type of excitation to be used in constructing the synthetic speech. The results of various implementations of this speech coder are presented for comparison. This work demonstrates that a...
Topics: DTIC Archive, Moore, James T, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *CLASSIFICATION, *SPEECH,...
A study of the feasibility of realizing a compact, multiple function speech processor using digital signal processing integrated circuits is presented in this report. The processor is required to accommodate a 2400 bps Linear Predictive (LPC-10) vocoder, a 9600 bps Adaptive Predictive (APC) vocoder, and wireline modems at the corresponding data rates. Architectures employing the Texas Instruments TMS32010 and the Fujitsu MB8764 digital signal processing integrated circuits appeared to be most...
Topics: DTIC Archive, Singer,E, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *VOCODERS, ALGORITHMS,...
This document reports on work toward a very low rate phonetic vocoder and a multirate speech compression system. The phonetic vocoder consists of a phonetic recognizer based on a trained diphone network, and a natural phonetic synthesizer which also uses diphone templates as a model for speech. This quarter several new diphones were added to the data base. There are currently 2845 diphones. We tested the phonetic recognition program, and made improvements to improve its speed and performance.
Topics: DTIC Archive, Berouti, Michael, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH COMPRESSION,...
This document reports progress in the development of a phonetic speech synthesis algorithm, implementation and development of a real-time LPC (Linear Predictive Coding) vocoder. Testing of spectral modeling using adaptive lattice methods, and results of a subjective evaluation of the mixed source excitation in LPC synthesis. A new diphone utterance data base has been designed and is being recorded for the phonetic synthesis program. Keywords include: Voice-excited coder and high-frequency...
Topics: DTIC Archive, Cosell, L, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH COMPRESSION, *VOICE...
The objective of the study was to relate device technology developments to voice terminal concepts and designs, in order to better understand the steps that would eventually lead to very small and inexpensive narrowband terminal implementations. The overall conclusion derived from this effort can be summarized as follows: Given the present and near future advances in technology it is predictable that present-day vocoder algorithms will soon be implementable as low cost compact devices. How soon...
Topics: DTIC Archive, Gold, Bernard, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH, *VOICE...
An assessment of automatic speech processing technology is presented. Fundamental problems in the development and the deployment of automatic speech processing systems are defined and a technology forecast for speech systems is presented.
Topics: NASA Technical Reports Server (NTRS), MAN MACHINE SYSTEMS, TECHNOLOGY ASSESSMENT, VOICE DATA...
Topics: DTIC Archive, McAulay, R. J., MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *VOCODERS,...
Air-mobile speech communication applications share robustness and noise immunity requirements with other mobile applications. The quality requirements are stringent, especially in the cockpit where air safety is involved. Based on these considerations, a decision was made to test an intermediate data rate such as 8.0 and 9.6 kb/s as proven technologies. A number of vocoders and codec technologies were investigated at rates ranging from 2.4 kb/s up to and including 9.6 kb/s. The proven vocoders...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT COMMUNICATION, CODERS, DECODERS, MOBILE...
This report describes the design and development of a real-time baseband LPC speech coder that transmits high-quality speech over a 9600 bps synchronous channel with bit-error rates of up to 1%. Presented are the results of our investigation of a number of aspects of the baseband LPC coder with the goal of maximizing the quality of the transmitted speech. Important among these aspects are: baseband width, baseband coding, high-frequency regeneration, and error-protection of important...
Topics: DTIC Archive, Viswanathan,R, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH TRANSMISSION, *VOICE...
The report summarizes the results of a program of research on communication system evaluation from the standpoint of speech intelligibility and speaker recognizability. The history and present status of the Diagnostic Rhyme Test (DRT) Form III are described along with the results of research relating to the validity of the DRT in various applications.
Topics: DTIC Archive, Voiers, William D, SPERRY RAND RESEARCH CENTER SUDBURY MA, *SPEECH, SPEECH...
The activities of the Psychometrics Department of TRACOR, Inc., fall into two major categories. In the first category are research activities undertaken with the aim of developing improved methods for evaluating voice communication systems and devices. In the second category are testing services performed with processed speech materials supplied by the contract monitor. The research activities included five major research projects from which technical papers resulted presented in the report.
Topics: DTIC Archive, Voiers, William D, TRACOR INC AUSTIN TX, *INTELLIGIBILITY, *SPEECH, *VOICE...
The author discusses methods and problems of acoustic signal processing for systems to enable machines to understand spoken communication. Emphasis is on research outside of the ARPA-sponsored SUR (Speech Understanding Research) study. This acoustic level processing includes three steps, not necessarily distinct: (1) preprocessing the original analog signal or its digitized form by basic techniques such as amplitude compression; (2) analysis of the preprocessed signals using fast Fourier...
Topics: DTIC Archive, Hoffman, A S, RAND CORP SANTA MONICA CA, *ACOUSTIC SIGNALS, *SIGNAL PROCESSING,...
This report summarizes our results of Voice encoding and video encoding using adaptive delta modulation. Topics include: packet loss, algorithm adaptation, variable rate algorithms, silence detection algorithms, design of a packet voice transmission system, slow-scan video encoding, packet destruction and frame-change detection.
Topics: DTIC Archive, Dhadesugoor, V R, CITY COLL NEW YORK COMMUNICATIONS SYSTEMS LAB, *DELTA MODULATION,...
This thesis proposes a new analysis/synthesis procedure for speech and image compression. The algorithm applies the discrete wavelet transform to subject data in order to obtain a set of multiresolution wavelet coefficients. The wavelet coefficients are then encoded by using the generalized Lloyd algorithm. The statistical properties of the wavelet coefficients are utilized to determine the number of resolution levels as well as the codebook size at each resolution level. Coding results show...
Topics: DTIC Archive, Erdemir, Alper, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *CODING, *QUANTIZATION,...
This report describes techniques that provide increased jam resistance for digitized speech. Methods for increasing the jam resistance of pulse code modulated data are analyzed and evaluated in listener tests. Special emphasis is placed on new voice encoding approaches that take advantage of a spread spectrum system with a variable (or multiple)-data-rate/variable (or multiple)-AJ capability. Methods for matching a source to a channel in a jamming environment are investigated. Several...
Topics: DTIC Archive, Poole,M A, MITRE CORP BEDFORD MA, *Antijamming, *Vocoders, *Voice communications,...
An introduction to vocoders is presented. An elementary discussion of speech fundamentals is followed by a brief description of the different branches of speech research work. Explanations are presented of channel vocoders, voice-excited vocoders and, finally, the vocoder built for this research.
Topics: DTIC Archive, Gold, Bernard, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH, *VOCODERS,...
This report describes a phoneme vocoder capable of transmitting compressed speech data over bandlimited communication channels at rates lower than 200 bits per second. Using linear prediction analysis for parameter extraction, and sophisticated segmentation and labeling techniques, the vocoder analyzer codes the incoming speech signal into a sequence of discrete sound units, or phonemes. At the receiving end of the channel, the phoneme sequence is input to a digital speech synthesizer. An area...
Topics: DTIC Archive, Oshika,B T, SYSTEM DEVELOPMENT CORP SANTA MONICA CALIF, *SPEECH RECOGNITION, *SPEECH...
The APC/SQ and LPC-10 Speech Algorithms are evaluated for their performance in a fading channel, listener evaluation is performed for recognition of the Phonetic Alphabet. Keywords include: Scintillation; Striations; Speech; LPC-10; APC/SQ; A/D; Speech Intelligibility; Phonetic Alphabet; and VOCODER.
Topics: DTIC Archive, Trebaol,George O, MAXIM TECHNOLOGIES INC SANTA CLARA CA, *CHANNELS, *INTELLIGIBILITY,...
This study is aimed at the broad goal of the DoD Secure Voice Consortium to develop hardware models of improved narrow-band voice coders. The study is focused on the 'pitch and voicing' problem. The objective is to conceive and demonstrate the feasibility of two or more improved strategies to estimate and encode the excitation parameters of human speech. The decoded parameters will be used to excite a time-varying vocal tract 'filter' in the synthesizer.
Topics: DTIC Archive, Magill, D T, STANFORD RESEARCH INST MENLO PARK CA, *CODING, *SPEECH RECOGNITION,...
This document is devoted to and analysis of the intelligibility of semantically anomalous sentences presented in four acoustically different conditions: (1) natural speech, no noise; (2) vocoded speech, no noise; (3) vocoded speech, noise added to the pitch track; (4) vocoded speech, noise to the spectrum. One objective was to analyze the specific types of errors in each conditions. The other objective was to compare results of this analysis with results obtained from the Diagnostic Rhyme Test...
Topics: DTIC Archive, Mack,M A, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH RECOGNITION,...
This paper is concerned with a generic class of predictive speech coders that includes the newly proposed Self Excited Vocoder (SEV) and the well known Code-Excited Linear Predictive Coder (CELPC). All members of this class form an excitation sequence for a linear predictive model filter using the same general model for the excitation signal. The general excitation model is based on a block coding technique where each sequence is drawn from an ensemble of sequences. This paper reports on two...
Topics: NASA Technical Reports Server (NTRS), COUNTERS, SELF EXCITATION, VOCODERS, VOICE COMMUNICATION,...
The Packet Speech Measurement Facility (PSMF) is an investigative tool designed to be used by researchers in packet network studies. The PSMF facilitates experiments dealing with the timing and composition of packet flow, and will help elucidate the interactions between the conceptual structures of protocol design and the physical exigencies of network implementation. This report summarizes efforts undertaken by the Computer Corporation of America during the second year of PSMF development:...
Topics: DTIC Archive, Low, David, COMPUTER CORP OF AMERICA CAMBRIDGE MA, *SPEECH, COMPUTER PROGRAMS,...
During the course of this contract, there have been several major task areas: the development of homomorphic signal processing techniques and their application to the development of a homomorphic vocoder and other signal processing applications; the development and implementation of techniques for enhancement and bandwidth compression of degraded speech; the development and evaluation of techniques for processing of multidimensional signals and the application of these techniques to image...
Topics: DTIC Archive, Oppenheim, A V, MASSACHUSETTS INST OF TECH CAMBRIDGE, *DIGITAL SYSTEMS, *SIGNAL...
Diagnostic speech intelligibility tests were evaluated to assess vulnerability of two different 2400 bit-per-second linear predictive vocoder algorithms to random bit errors imposed on the data stream. Listening tests with crews of eight subjects yielded diagnostic intelligibility scores at zero, 1%, 3% and 5% bit error rates. These data were analyzed to establish linear regression models relating intelligibility performance and bit error rate. Piecewise-linear prediction coding (PLPC) was...
Topics: DTIC Archive, Smith, Caldwell P., ELECTRONIC SYSTEMS DIV HANSCOM AFB MA, *SPEECH RECOGNITION,...
This appendix to Lincoln Laboratory Technical Note 1976-37 provides all of the detailed drawings, layouts and cabling information to construct an identical vocoder to the one described in the technical note. The additional comments may clear up any additional questions concerning this appendix.
Topics: DTIC Archive, Hofstetter, Edward M., MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB,...
This report describes the design and construction of prototype portable voice communication units and the implementation of the BBN robust 16 kbit/s adaptive predictive coding algorithm as a full-duplex real-time speech coder on these units. The report documents the hardware and software design and implementation efforts, and presents the results of a hardware production cost study. Work on algorithm simplification of the BBN 2.4 kbit/s harmonic deviations LPC speech coder is also described....
Topics: DTIC Archive, Tiao,J, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *ANALOG TO DIGITAL CONVERTERS,...
An assessment of the applications of automatic speech recognition to defense communication systems is presented. Future research efforts include investigations into the following areas: (1) dynamic programming; (2) recognition of speech degraded by noise; (3) speaker independent recognition; (4) large vocabulary recognition; (5) word spotting and continuous speech recognition; and (6) isolated word recognition.
Topics: NASA Technical Reports Server (NTRS), DEFENSE COMMUNICATIONS SYSTEM (DCS), MAN MACHINE SYSTEMS,...
In order to determine if speech whose fundamental is absent can have its pitch accurately restored so as to be used as an input to a vocoder, a computer simulation was performed. The fundamental was restored by passing the speech through a fullwave rectifier followed by a slope filter. The accuracy of the pitch restoration of this method was compared with that of simply measuring the pitch of speech whose fundamental was present by slope filtering alone. A third pitch detection method, that of...
Topics: DTIC Archive, Goldberg, A J, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SPEECH RECOGNITION,...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
When a person listens to speech corrupted by noise or other adverse environmental factors, speech intelligibility may be impaired slightly or not at all. The same corrupted speech, after being vocoded, often causes drastic intelligibility loss. The is due to the fact that the human peripheral auditory system is a superior signal processor to that of the vocoder. This report is based on the premise that a vocoder analyzer that better resembles the peripheral auditory system would function in a...
Topics: DTIC Archive, Gold,B, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *Vocoders, *Speech...
This report discusses work on converting the output of the adaptive predictive coder into a fixed-rate bit-stream, and on improving the coded speech quality by means of various noise shaping filters. Also discussed are the computational complexity of the algorithm.
Topics: DTIC Archive, Krasner,M, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *ALGORITHMS, *CODING, ADAPTIVE...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
The results of previous technical reports are summarized and the results of tests of various recently developed speech compression systems are presented and analyzed. The results can be summarized as follows: (1) Semi- vocoders, operating at 9600 bits/sec, and channel vocoders, at 2400 bits/sec, will provide speech of adequate intelligibility and quality for most military communications. The voice quality of the semi-vocoders will usually be somewhat superior to that of the channel vocoders....
Topics: DTIC Archive, Kryter, Karl D, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH COMPRESSION,...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
This report describes the initial investigation of a new synthetic speech system based on a line spectrum pair (LSP) representation of the speech spectral envelope. The system contains a library of stored LSP speech segments extracted from natural speech. These segments are modified as necessary by a small set of context-sensitive rules and then concatenated to generate high- quality, natural-sounding speech. Tests of a preliminary system produced Modified Rhyme Test and Diagnostic Rhyme Test...
Topics: DTIC Archive, Everett, Stephanie S, NAVAL RESEARCH LAB WASHINGTON DC, *SYNTHESIS, *SPEECH...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
We report on research toward a very-low-rate vocoder. This quarter we continued investigation in three areas. The first area of research is multi- speaker synthesis: speech synthesis from the transmitted vocoder parameters with the voice quality of the vocoder user. This processing entails speaker-specific spectral transformation of the vocoder diphone database. The second area of research is to improve the accuracy of the phonetic recognition. Our work this quarter concentrated on training the...
Topics: DTIC Archive, Makhoul, John, BOLT BERANEK AND NEWMAN INC CAMBRIDGE MA, *SPEECH ARTICULATION,...
Speech quality measurement is considered from three points of view: subjective testing; objective testing; and communicability testing. Speech quality is interpreted here in terms of user acceptability. Subjective testing is considered from the philosophical perspective of iso-preference, relative preference, and absolute-preference, with isometric and parametric test methodologies, with the results of PARM and QUART as a basis. It is felt that the best approach for future subjective testing...
Topics: DTIC Archive, Barnwell, T. P., III., GEORGIA INST OF TECH ATLANTA SCHOOL OFELECTRICAL ENGINEERING,...
A real time harmonic pitch detection algorithm has been developed on the Lincoln Digital Voice Terminal (LDVT). The algorithm was designed to be fast and to perform well when the input speech is degraded (i.e., telephone quality) or corrupted with acoustically coupled noise. The algorithm determines the fundamental frequency from the spacing between harmonics in a selected portion of the spectrum. The algorithm was incorporated into a real time linear prediction vocoder and compared favorably...
Topics: DTIC Archive, Seneff, Stephanie, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *PITCH...
