Speech Fundamental Frequency Research Articles

Laryngographic changes following endotracheal intubation in adults.

ABSTRACTLaryngographic records were taken from twelve adults to determine if there are any quantifiable changes in voice following endotracheal intubation for anaesthesia. Two changes were seen in the Fx histograms between the pre‐ and post‐intubation records. Firstly an increased low tone scatter and secondly an increase in the fundamental frequency of speech. Using these measures the post‐operative hoarse voice can be quantified.

A new algorithm for speech fundamental frequency estimation

In this correspondence, we present a method of detecting the frequency based on the recognition of fundamental peaks of a low-pass filtered (f c = 0.7 kHz) speech signal. Average overall recognition accuracy of approximately 99 percent for the training speech sample and 97.5 percent for a test speech sample were achieved. The experimental verification of the developed FPR (fundamental peak recognition) method also included an objective comparison to Miller's data reduction method, and a subjective performance evaluation using the standard cepstrum method. The FPR classification scheme is computationally efficient and easily implementable with relatively slow 8-bit microprocessors.

Declination.: a review and some hypotheses

One of the most widespread – and widely studied – properties of speech fundamental frequency (Fo) is a tendency to decline gradually during the course of utterances. This tendency has been given a variety of names, of which the best known is probably DECLINATION. This is the term I shall use in this paper. The purpose of the paper is to review past work on declination as it affects the phonological and phonetic modelling of Fo contours, and to outline some ideas for the empirical resolution of the issues that emerge from the discussion.

Linguistic modality effects on fundamental frequency in speech.

This paper examines the effects on fundamental frequency (F0) patterns of modality operators, such as sentential adverbs, modals, negatives, and quantifiers. These words form inherently contrastive classes which have varying tendencies to produce emphasis deviations in F0 contours. Three speakers read a set of 186 sentences and three paragraphs to provide data for F0 analysis. The important words in each sentence were marked intonationally with rises or sharp falls in F0, compared to gradually falling F0 in unemphasized words. These emphasis deviations were measured in terms of F0 variations from the norm; they were larger toward the beginning of sentences, in longer sentences, on syllables surrounded by unemphasized syllables, and in contrastive contexts. Other results showed that embedded clauses tended to have lower F0, and negative contractions were emphasized on their first syllables. Individual speakers differed in overall F0 levels, while using roughly similar emphasis strategies. F0 levels changed in paragraphs, with emphasis going to contextually new information.

Differential sensitivity to pitch distance, particularly in speech.

The fundamental frequency in speech shows many rapid variations, part of which determine the perceived shape of the pitch contour. This implies that the accuracy with which listeners perceive changes of F0 is more relevant to understanding the perception of intonation than the traditional just noticeable difference of F0 in speech. This study examines the sensitivity to differences in the amount of change of F0, upward (Experiment Ia) and downward (Experiment Ib). Subjects 74 and 104, respectively, with widely different musical ability can be divided into three categories: (1) Quite a number of them were not able to discriminate differences of less than 4 semitones (nondiscriminators); (2) other subjects wrongly tried to base their judgments on a simple comparison of the final pitches of a stimulus pair (final pitch discriminators); (3) the remaining subjects (pitch distance discriminators) yielded average jnd's of about 1.5 to 2 semitones. Since the issue is associated with musical interval sense, similar experiments were carried out using piano tones. The results were essentially the same as with the speech stimuli. The outcome suggests that only differences of more than 3 semitones play a part in communicative situations.

The effect of communications medium on the fundamental frequency of speech

Interactions between two pairs of subjects were conducted face‐to‐face and over a two‐way closed‐circuit television medium and were tape recorded. The speech for each subject over each medium was edited to remove silent intervals and the resulting edited speech segments, each about 1 minute in duration, were analyzed by a computer implementation of the cepstrum method of fundamental‐frequency determination. The speech of all four subjects showed a statistically significant rise in fundamental frequency ranging from 3.89% to 7.83% for the closed‐circuit television condition relative to the face‐to‐face condition. This result could imply that two‐way closed‐circuit television is a more tense or stressful medium than face‐to‐face communication. Alternatively, the effect could be explained by such other factors as a rise in speech level caused by a greater perceived distance between the participants in the closed‐circuit television condition.

A SYSTEM FOR MONITORING AND CONDITIONING MODAL FUNDAMENTAL FREQUENCY OF SPEECH1

A SYSTEM FOR MONITORING AND CONDITIONING MODAL FUNDAMENTAL FREQUENCY OF SPEECH¹