A new technique for the analysis of speech, the perceptual linear predictive (PLP) technique, is presented and examined. This technique uses three concepts from the psychophysics of hearing to derive an estimate of the auditory spectrum: (1) the critical-band spectral resolution, (2) the equal-loudness curve, and (3) the intensity-loudness power law. The auditory spectrum is then approximated by an autoregressive all-pole model. A 5th-order all-pole model is effective in suppressing speaker-dependent details of the auditory spectrum. In comparison with conventional linear predictive (LP) analysis, PLP analysis is more consistent with human hearing. The effective second formant F2' and the 3.5-Bark spectral-peak integration theories of vowel perception are well accounted for. PLP analysis is computationally efficient and yields a low-dimensional representation of speech. These properties are found to be useful in speaker-independent automatic-speech recognition.

Perceptual linear predictive (PLP) analysis of speech

A spreading activation theory of retrieval in sentence production

https://www.cogsci.ucsd.edu/~nunez/COGS160/Rizzolatti_Arbib_PS.pdf

Language within our grasp

https://apps.dtic.mil/sti/pdfs/ADA157550.pdf

The TRACE model of speech perception.

The generation of words in speech involves a number of processing stages. There is, first, a stage of conceptual preparation; this is followed by stages of lexical selection, phonological encoding, phonetic encoding and articulation. In addition, the speaker monitors the output and, if necessary, self-corrects. Major parts of the theory have been computer modelled. The paper concentrates on experimental reaction time evidence in support of the theory.

/pdf/a-theory-of-lexical-access-in-speech-production-56yj14t9eb.pdf

A theory of lexical access in speech production

A software formant synthesizer is described that can generate synthetic speech using a laboratory digital computer. A flexible synthesizer configuration permits the synthesis of sonorants by either a cascade or parallel connection of digital resonators, but frication spectra must be synthesized by a set of resonators connected in parallel. A control program lets the user specify variable control parameter data, such as formant frequencies as a function of time, as a sequence of 〈time, value〉 points. The synthesizer design is described and motivated in Secs. I–III, and fortran listings for the synthesizer and control program are provided in an appendix. Computer requirements and necessary support software are described in Sec. IV. Strategies for the imitation of any speech utterance are described in Sec. V, and suggested values of control parameters for the synthesis of many English sounds are presented in tabular form.

Software for a cascade/parallel formant synthesizer

Voice quality variations include a set of voicing sound source modifications ranging from laryngealized to normal to breathy phonation. Analysis of reiterant imitations of two sentences by ten female and six male talkers has shown that the potential acoustic cues to this type of voice quality variation include: (1) increases to the relative amplitude of the fundamental frequency component as open quotient increases; (2) increases to the amount of aspiration noise that replaces higher frequency harmonics as the arytenoids become more separated; (3) increases to lower formant bandwidths; and (4) introduction of extra pole zeros in the vocal-tract transfer function associated with tracheal coupling. Perceptual validation of the relative importance of these cues for signaling a breathy voice quality has been accomplished using a new voicing source model for synthesis of more natural male and female voices. The new formant synthesizer, KLSYN88, is fully documented here. Results of the perception study indicate that, contrary to previous research which emphasizes the importance of increased amplitude of the fundamental component, aspiration noise is perceptually most important. Without its presence, increases to the fundamental component may induce the sensation of nasality in a high-pitched voice. Further results of the acoustic analysis include the observations that: (1) over the course of a sentence, the acoustic manifestations of breathiness vary considerably--tending to increase for unstressed syllables, in utterance-final syllables, and at the margins of voiceless consonants; (2) on average, females are more breathy than males, but there are very large differences between subjects within each gender; (3) many utterances appear to end in a "breathy-laryngealized" type of vibration; and (4) diplophonic irregularities in the timing of glottal periods occur frequently, especially at the end of an utterance. Diplophonia and other deviations from perfect periodicity may be important aspects of naturalness in synthesis.

/pdf/analysis-synthesis-and-perception-of-voice-quality-1q0nbgfn1a.pdf

Analysis, synthesis, and perception of voice quality variations among female and male talkers

The pattern of durations of individual phonetic segments and pauses conveys information about the linguistic content of an utterance. Acoustic measures of segmental timing have been used by many investigators to determine the variables that influence the durational structure of a sentence. The literature on segmental duration is reviewed and related to perceptual data on the discrimination of duration and to psychophysical data on the ability of listeners to make linguistic decisions on the basis of durational cues alone. We conclude that, in English, duration often serves as a primary perceptual cue in the distinctions between (1) inherently long verses short vowels, (2) voiced verses voiceless fricatives, (3) phrase‐final verses non‐final syllables, (4) voiced versus voiceless postvocalic consonants, as indicated by changes to the duration of the preceding vowel in phrase‐final positions, (5) stressed verses unstressed or reduced vowels, and (6) the presence or absence of emphasis.Subject Classification...

Linguistic uses of segmental duration in English: Acoustic and perceptual evidence

The automatic conversion of English text to synthetic speech is presently being performed, remarkably well, by a number of laboratory systems and commercial devices. Progress in this area has been made possible by advances in linguistic theory, acoustic-phonetic characterization of English sound patterns, perceptual psychology, mathematical modeling of speech production, structured programming, and computer hardware design. This review traces the early work on the development of speech synthesizers, discovery of minimal acoustic cues for phonetic contrasts, evolution of phonemic rule programs, incorporation of prosodic rules, and formulation of techniques for text analysis. Examples of rules are used liberally to illustrate the state of the art. Many of the examples are taken from Klattalk, a text-to-speech system developed by the author. A number of scientific problems are identified that prevent current systems from achieving the goal of completely human-sounding speech. While the emphasis is on rule programs that drive a format synthesizer, alternatives such as articulatory synthesis and waveform concatenation are also reviewed. An extensive bibliography has been assembled to show both the breadth of synthesis activity and the wealth of phenomena covered by rules in the best of these programs. A recording of selected examples of the historical development of synthetic speech, enclosed as a 33 1/3-rpm record, is described in the Appendix.

Review of text‐to‐speech conversion for English

The voice onset time (VOT) and the duration of the burst of frication noise at the release of a plosive consonant were measured from spectrograms of word-initial consonant clusters. Mean data from ...

Dennis H. Klatt

Papers

Software for a cascade/parallel formant synthesizer

Analysis, synthesis, and perception of voice quality variations among female and male talkers

Linguistic uses of segmental duration in English: Acoustic and perceptual evidence

Review of text‐to‐speech conversion for English

Voice onset time, frication, and aspiration in word-initial consonant clusters.