Conrad LaRiviere

Vocalic transitions in the perception of voiceless initial stops

Two experiments were conducted in order to test the transition dependency and integration hypotheses of speech perception. These two models emphasize the importance of vocalic transitions in stop−vowel syllables for different reasons. The transition−dependency model regards the vocalic transition as a primary cue for stop identification, and the integration model holds that the transition prevents backward masking. Nine stop−vowel monosyllables were treated, resulting in a set of (1) syllables in which the vocalic transition was deleted (Experiment 1), and (2) various nonsyllabic segments—the aperiodic portion, the aperiodic portion plus the vocalic transition, the vocalic transition, and the vocalic transition plus the vowel (Experiment 2). Recognition scores obtained for these stimuli indicate that the vocalic transition is neither a sufficient nor necessary cue for voiceless stop recognition and that the aperiodic portion of the consonant carries the heaviest perceptual load.Subject Classification: 70.30.

Contributions of Fundamental Frequency and Formant Frequencies to Speaker Identification

This experiment in aural speaker identification attempts to ascertain the relative contributions of fundamental frequency and formant frequencies. Speech samples were four voiced, whispered, and low-p

Characteristics of ultrasonic vocalizations emitted by rats during shock-elicited aggression

Albino rats tested for shock-elicited aggression on occasion emitted periodic ultrasonic calls. The fundamental frequency of these calls was about 24 kHz, with harmonics appearing at 72 and 120 kHz, and the calls lasted as long as 3–4 sec. These calls were emitted by rats which had adopted an upright submissive posture following attack(s). These long 22–26-kHz calls may serve to inhibit or prevent unlearned behaviors in rats.

Perception of Word Boundaries under Conditions of Lexical Bias

The unitary hypothesis of sentence perception implies a decoding process wherein listeners anticipate or confirm lexical units according to received syntactic information. A test of this hypothesis wa

Comments on summarization of the findings of Liberman etal. regarding the role of formant transitions in the perception of voiceless stops

In a recent paper [LaRiviere et al., J. Acoust Soc. Am. 57, 470–475 (1975)], the term ’’vocalic transition’’ was introduced with reference to an hypothesis generated by the authors. In this letter, a distinction is drawn between vocalic transition and formant transition with respect to literature citations.Subject Classification: 70.30, 70.70.

Recognition Memory for the Deep-Structure Propositions of Sentences

This study tested a model concerning the structure underlying the retention of complex sentences; in the model, the deep structure constituent propositions of the multi-proposition sentences are hierarchically related. Latencies and error rated to recognize these constituent propositions as true or false were measured and were the same for all propositions. These results did not confirm the model but showed that for recognition (but not necessarily for other memory tasks), each deep proposition of a sentence is separately or equally accessible. Stated differently, the recognition process does not make use of hierarchical organizations. The findings were obtained while the imagery-arousing capacity of the deep propositions was controlled. In previous research imagery was not controlled and it was found that some propositions and idea-units were better remembered than others; consequently, the suggestion was made that imagery might be related to accessibility, in that high-imagery items might be more accessible than low-imagery items. Closer analysis of other aspects of the findings indicated that another interesting factor might also be operating.