Kenneth F. Ruder

Effects of verbal imitation and comprehension training on verbal production

This study sought to determine whether some combination of imitation training and comprehension training was necessary to achieve verbal production or whether comprehension training alone was sufficient to result in verbal production. Fifty-one first- and second-grade subjects were trained to imitate eight words (Spanish nouns) for which there were no referents. An additional set of eight words was trained in a comprehension task where overt verbal rehearsal was prohibited. Once criterion of two successive sessions of 100% performance was reached in training for both imitation and comprehension, training modes were reversed so that items initially trained in imitation were then trained in comprehension andvice versa. Results showed that initial comprehension training did result in some verbal production, whereas initial imitation training, as expected, did not. A marked improvement in verbal production performance was observed when initial comprehension training was followed by imitation training. When initial imitation training was followed by comprehension training, verbal production also resulted but not to the degree or with the consistency of performance which marked the comprehension-then-imitation sequence. Furthermore, comprehension training required more trials to reach a similar level of proficiency when it followed imitation training than when it preceded imitation. These data indicate that initial imitation training interferes with acquisition of subsequent comprehension and production responses and that the preferred training sequence is one which initially focuses on comprehension and follows this with verbal imitation.

DURATION OF SILENT INTERVAL AS A PERCEPTUAL CUE OF SPEECH PAUSES

The effect of duration of silent interval on the perception of pauses in speech was investigated. The stimuli consisted of 5 recorded sentences within which the words “lost” and “contact” were manipulated so that their syntactic relation to one another varied in complexity from sentence to sentence. Ss, working individually, mechanically adjusted the silent interval duration between the words “lost” and “contact” within each sentence in order to make judgments of (1) the pause-detection threshold, (2) the optimal fluent pause, and (3) the minimal hesitation pause. Across the 5 sentences, the mean durations were 23 msec., 186 msec., and 505 msec. for the three types of pause, respectively. Statistical analysis, however, showed that durations of silent interval for these three types of pause differed significantly only when occurring between phrases. This was not true of within-phrase pauses. Thus, contrary to usual assumptions in the literature, these results suggest that for within-phrase pauses, at least, duration of silent interval is an insufficient perceptual cue for differentiation of fluent and hesitation pauses.

Speech Discrimination in Black and White Children

The effect of dialect on speech discrimination scores of black and white adolescents was investigated. Ten black and ten white tenth grade students were selected as subjects. Six public school teachers, three black and three white, read the Kindergarten PB Word Lists which served as the stimuli for the speech discrimination tests. These words were played back to each student at three different listening levels. The students were requested to write the words they heard. Results showed that both black and white students did significantly better in their performances on speech discrimination tests when white teachers served as speakers. There was no significant difference between the performance of black and white students when white teachers were speakers. However, when black teachers served as speakers, black students performed significantly better than white students on the discrimination tests at the two lowest intensity levels.

Pause adjustment mechanism and measurement system (PAMMS)

A system is described whereby silent interval duration may be studied as a parameter in the perception of speech pauses under controlled conditions. PAMMS (pause adjustment mechanism and measurement system) provides the S (or the E) with the unique capability of directly manipulating a pause which is then automatically measured electronically. The system includes electronic devices which provide for a specialized switching and dubbing procedure by means of which test tapes are generated.

A method for the precise switching of speech

A simple procedure by which a speech signal may be switched on or off (or from one ear to the other) at a precise instant of time is described. The speech sample is first recorded on a magnetic tape loop. A reference pulse is then recorded preceding the speech signal. This reference pulse triggers an adjustable time delay which in tum operates an electronic switch at an appropriate time.

Context effects on silent interval estimation in speech and nonspeech environments

The speech stimuli for this experiment were derived from two sentences, each containing the words free criminals. In one sentence, the words free criminals occurred intraphrase and in the other sentence they occurred interphrase. The vowel duration in free and the silent interval preceding criminals were systematically and independently varied. Vowel durations of 100, 200, 300, 400, 500, and 600 msec were paired with silent intervals of 0, 50, 100, 150, 250, and 500 msec. Subjects were asked to make direct magnitude estimates of the silent interval duration between free and criminals. Power‐law scaling exponents for judgments versus vowel duration and silent interval duration were 0.29 and 0.48, respectively. The above experimental procedure was repeated in two experiments using nonspeech stimuli with temporal characteristics similar to the two sentences. In particular, the silent interval to be estimated occurred between two 1000‐Hz tones. In Experiment 1 the duration of the tone preceding the silent int...

Silent Interval and Vowel Duration Effects on Pause Magnitude Estimation in Intrapause and Interpause Environments

The stimuli for this experiment were derived from two sentences, each containing the words free criminals. In one sentence these two words occurred within a phrase, and in the other sentence a phrase boundary occurred between the words. The vowel duration in free and the silent interval preceeding criminals were systematically and independently varied. Vowel durations of 100, 200, 300, 400, 500, and 600 msec were paired with silent intervals of 0, 50, 100, 150, 250, and 500 msec for both sentences. Subjects were asked to make direct magnitude estimates of the perceived pause between free and criminals in each of the stimulus sentences. Results indicated that given durations of vowel and silent interval result in similar perceived pauses in intraphrase position than in interphrase position. Power law scaling exponents were larger for vowel duration than for silent interval in all conditions. [This research supported by the National Institutes of Health.]

Silent Interval Duration as a Perceptual Cue of Speech Pauses

The effect of silent‐interval duration on the perception of pauses in speech was investigated. The stimuli consisted of five recorded sentences within which the words “lost” and “contact” were manipulated so that their syntactic relation to one another varied in complexity from sentence to sentence. Twelve subjects, working individually, mechanically adjusted the silent‐interval duration between the words “lost” and “contact” within each sentence in order to locate (1) the pause detection threshold, (2) optimal fluent pause duration, and (3) minimal hesitation pause duration. Across the five sentences, the mean durations were 6, 186, and 505 msec, for the three pause types, respectively. Statistical analysis, however, showed that silent interval durations for these three pause types differed significantly only when occurring between phrases. This was not true of within‐phrase pauses. Thus, contrary to usual assumptions in the literature, these results suggest that for within‐phrase pauses, at least, silen...