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L A Streeter

Publications and source records attributed to L A Streeter.

7 recordsLinked to original sources
PubMed1979

The role of medial consonant transitions in word perception.

In VCV nonsense forms (such as /epsilondepsilon/, while both the CV transition and the VC transition are perceptible in isolation, the CV transition dominates identification of the stop consonant. Thus, the question arises, what role, if any, do VC transitions play in word perception? Stimuli were two-syllable English words in which the medial consonant was either a stop or a fricative (e.g., "feeding" and "gravy"). Each word was constructed in three ways: (1) the VC transition was incompatible with the CV in either place, manner of articulation, or both; (2) the VC transition was eliminated and the steady-state portion of first vowel was substituted in its place; and (3) the original word. All versions of a particular word were identical with respect to duration, pitch contour, and amplitude envelope. While an intelligibility test revealed no differences among the three conditions, data from a paired comparison preference task and an unspeeded lexical decision task indicated that incompatible VC transitions hindered word perception, but lack of VC transitions did not. However, there were clear differences among the three conditions in the speeded lexical decision task for word stimuli, but not for nonword stimuli that were constructed in an analogous fashion. We discuss the use of lexical tasks for speech quality assessment and possible processes by which listeners recognize spoken words.

Adolescent↗
PubMed1978

Acoustic determinants of phrase boundary perception.

How three supersegmental variables (amplitude, pitch contour, and duration pattern) influence phrase boundary perception was investigated in two studies. Listeners located the phrase boundary in ambiguous algebraic expressions, such as "(A plus E) times O" and A plus (E times O)." In one experiment, two values of each of three variables (appropriate or neutral) were orthogonally varied, using linear predictive coding analysis-synthesis procedures. There was a total of eight manipulations for each expression. In the other, the three suprasegmental variables were exchanged between the two alternative meanings of an expression, yielding a total of eight manipulations for each expression. Results from the two studies were consistent in showing that listeners use all three cues, and just these three to parse such utterances. That is, it was possible to completely shift the meaning of an expression uttered with one meaning into its alternate meaning by exchanging all three variables. In both studies, the effects of duration pattern and pitch contour were additive in total proportion correct. Possible models of how listeners process pitch and duration information independently in making a parsing decision are discussed.

Adolescent↗
PubMed1977

Pitch changes during attempted deception.

Two studies on speech samples from 32 male college students are reported. In the first, it was shown that the average voice fundamental frequency of the subjects was higher when lying than when telling the truth. In the second, judges rated the truthfulness of 64 true and false utterances either from an audiotape that had been electronically filtered to render the semantic content unintelligible or from an unfiltered tape. The truthfulness ratings of the judges who heard the content-filtered tape were negatively correlated with fundamental frequency, whereas for the unfiltered condition, truthfulness ratings were uncorrelated with pitch. Although raings made under the two conditions did not differ in overalll accuracy, accuracy differences were found that depended on how an utterance had been elicited originally.

Arousal↗