James J. Jenkins

An effect of linguistic experience: The discrimination of [r] and [l] by native speakers of Japanese and English

To test the effect of linguistic experience on the perception of a cue that is known to be effective in distinguishing between [r] and [l] in English, 21 Japanese and 39 American adults were tested on discrimination of a set of synthetic speech-like stimuli. The 13 “speech” stimuli in this set varied in the initial stationary frequency of the third formant (F3) and its subsequent transition into the vowel over a range sufficient to produce the perception of [r a] and [l a] for American subjects and to produce [r a] (which is not in phonemic contrast to [l a ]) for Japanese subjects. Discrimination tests of a comparable set of stimuli consisting of the isolated F3 components provided a “nonspeech” control. For Americans, the discrimination of the speech stimuli was nearly categorical, i.e., comparison pairs which were identified as different phonemes were discriminated with high accuracy, while pairs which were identified as the same phoneme were discriminated relatively poorly. In comparison, discrimination of speech stimuli by Japanese subjects was only slightly better than chance for all comparison pairs. Performance on nonspeech stimuli, however, was virtually identical for Japanese and American subjects; both groups showed highly accurate discrimination of all comparison pairs. These results suggest that the effect of linguistic experience is specific to perception in the “speech mode.”

Recall for words as a function of semantic, graphic, and syntactic orienting tasks.

Two word lists were prepared for recall experiments. One consisted of moderately associated word pairs, the other of unrelated words. Each list was presented to 11 different groups of subjects (22 groups in all). The control group was simply instructed to remember the words; five groups performed orienting tasks but were not informed that they would have to recall the words; five groups performed the tasks and were informed about subsequent recall. Two orienting tasks required that subjects process the meaning of the words; two tasks required syntactic processing; and one task required processing the orthography of the word. Semantic tasks yielded much greater recall and greater organization of recall than the nonsemantic tasks. Intention to learn was important only with the associated list. Results were discussed in terms of processes involved in tasks rather than responses involved in tasks.

Dynamic specification of coarticulated vowels

This chapter summarizes research conducted over a 35 year period on the dynamic specification of vowels. A series of experiments comparing vowels in consonant context with vowels produced in isolation failed to support talker normalization theories that predicted higher accuracy through prior exposure to a talker’s “point vowels.” Instead, these studies showed that vowels in consonant context were more accurately identified than isolated vowels, supporting a dynamic specification of vowels theory over static target theories, leading to the proposal that important information is contained in the formant transitions. Consonant–vowel coarticulation is not a source of “noise”, rather it gives rise to an acoustic array in which the consonants and vowels are cospecified in the time-varying spectral configuration which we call dynamic specification. Subsequent experiments showed high identification accuracy for “silent center vowels” in which the central portion of the CVC syllable was removed by gating. Identification accuracy was not disrupted when the onset and offset portions were produced by different speakers. Vowel identification improved with increasing duration of the onsets or offset portions. Onsets were identified more accurately than offsets but neither was as well identified as the silent center syllables. Collectively these and other experiments summarized herein support the view that the most important source of information for speaker-invariant vowel identity is carried in dynamic specification of vowel onset and offset spectral patterns, with vowel duration also playing a role. Subsequent experiments with North German vowels, which do not exhibit the degree of vowel diphthongization reported in American English dialects, showed that listeners rely on dynamic spectro-temporal information specified by syllable onsets and offsets, in addition to cues provided by inherent vowel duration. Cross-language comparisons are presented from the perspective of adaptive dispersion theory. These comparisons support the view that dynamic properties are perceptually more important in differentiating vowels in languages with large vowel inventories.

THE 1952 MINNESOTA WORD ASSOCIATION NORMS

Publisher Summary This chapter discusses the 1952 Minnesota word association norms. The Minnesota word association norms are usually known as the Minnesota norms for the Kent–Rosanoff word association test. If the frequency of occurrence of responses to the particular stimulus word is tabulated and then arranged in order of descending frequency, it is customary to describe this series as the associative hierarchy or the associative response hierarchy for the particular stimulus word. There is a general negative relationship between the frequency of popular responses to stimuli and the number of different responses made to the stimuli. The norms have found a wide variety of uses in the experimental laboratory and have also provided a measure of individual differences. The norms provide an index of powerful verbal habits that are shared by members of the college student community.

Effects of orienting tasks on free recall in incidental learning: “difficulty,” “effort,” and “process” explanations

In three experiments involving 22 conditions, amount of free recall was shown to vary with type and combination of orienting task performed during the presentation of a list of 24 low-frequency English nouns. When the orienting task was semantic, that is, it required the subjects to process the meanings of words, recall was significantly higher than that of subjects performing nonsemantic orienting tasks. When two orienting tasks were performed serially during the presentation interval, and one of the tasks was semantic, recall was significantly higher than the recall of groups performing only nonsemantic tasks. When the two tasks were nonsemantic, recall was indistinguishable from the recall of subjects performing single nonsemantic tasks. When the incidental subjects performed a semantic task either singly or in combination with another task, recall was not significantly different from that of a control group of intentional learners who performed no orienting task. The findings are concordant with “process” explanations of the effects of orienting tasks and discordant with “difficulty” or “effort” theories.

Identification of vowels in "vowelless" syllables.

Traditionally, it has been held that the primary information for vowel identification is provided by formant frequencies in the quasi-steady-state portion of the spoken syllable. Recent search has advanced an alternative view that emphasizes the role of temporal factors and dynamic (time-varying) spectral information in determining the perception of vowels. Nine vowels spoken in /b/ + vowel + /b/ syllables were recorded. The syllables were modified electronically in several ways to suppress various sources of spectral and durational information. Two vowel-perception experiments were performed, testing subjects’ ability to identify vowels in these modified syllables. Results of both experiments revealed the importance of dynamic spectral information at syllable onset and offset (in its proper temporal relation) in permitting vowel identification. On the other hand, steady-state spectral information, deprived of its durational variation, was a poor basis for identification. Results constitute a challenge to traditional accounts of vowel perception and point toward important sources of dynamic information.

Role of Linguistic Experience in the Perception of Speech

Although the linguistic and psycholinguistic theories of the 1960s emphasized the predispositional and maturational aspects of language acquisition, no one denies that experiential variables have profound effects on all aspects of the development of language functions. The knowledge of a language possessed by a normal adult is a product of many years of exposure to a specific language environment. Both receptive and expressive modes of language behavior are molded by the speaker-hearer’s interaction with the linguistic community. In literate societies, the perceptual aspects of receptive language function include both vision (reading) and audition (speech perception), but, obviously, the latter is the primary mode by which language is learned and used by all normal humans. (For a comparison and contrast of the visual and auditory modes, see Kavanagh and Mattingly, 1972.)

The effects of cued orienting tasks on the free recall of words

Amount and organization of recall of word lists was shown to depend on the nature of the orienting tasks performed by subjects even when the task varied from word to word within a single list. Subjects heard a cue letter after each word designating the appropriate task to be performed. Experiment I used a list of unrelated words. Words to which subjects applied a semantic task (pleasantness rating) were more often recalled than words to which nonsemantic tasks were applied (estimation of number of letters or occurrences of the letter “e”). No significant difference in recall was observed between groups prewarned about the recall test and those groups not warned. Recalled words did not cluster significantly with respect to task. Experiment II presented a randomized list of high-strength associative pairs. One group of subjects performed the same task for both members of an associative pair; the other group used pair members in different tasks. The semantic task again led to greater recall than nonsemantic tasks. Associative clustering in the same-task condition was greater than in the different-tasks condition. Both meaningfulness of task and task similarity contribute to clustering.

The effects of associative strength and response hierarchy on paired-associate learning

Summary Two experiments were designed to assess the influence of free-associative strength on the paired-associate learning of children. In each, three groups of fourth-grade children learned lists of ten verbal paired-associates which varied in average associative strength between the stimulus words and the responses. Group I learned a list composed of stimuli and their primary normative responses, five of which were relatively strong and five of which were relatively weak; Group II learned a list composed of the same ten stimuli and responses which occurred to them with an intermediate normative frequency; and Group III learned a list composed of the same stimuli and responses of very low normative frequency. In Experiment I, ease of learning varied with the average associative strength of the pairs at all levels; and differential performance was obtained on Lists I and II between the pairs with stimuli which elicit relatively high-strength primary responses and those which elicit relatively low-strength primary responses. Performance on the former was better than on the latter. Experiment II differed from Experiment I only in that the Ss had a study trial on the lists before learning trials began. The results essentially paralleled those of Experiment I. Such findings have not been obtained with adults and were interpreted as representing differences due to natural language habits of differential strengths. The findings with regard to the differential performance on the two types of pairs were discussed as indications that the forced-frequency nature of the single response normative data caused the relative strengths of the responses following high-strength primary responses to be underestimated when based on absolute normative frequencies.

Recall of passages of synthetic speech

Memory for synthetic speech versions of grade school-level materials was tested in two studies. In Experiment 1, two different versions of three simple stories were recorded in synthetic speech. The versions differed in prosody, one employing hand-applied pitch and stress and the other employing random stress. Free recall of the stories showed no consistent difference in performance as a function of the intonational pattern used. Experiment 2 compared the recall of a simple biographical sketch presented in either natural speech or synthetic speech. A sentence-by-sentence dictation test showed little difference in intelligibility of the texts, and the difference disappeared with minimal practice on synthetic speech. Free recall of the entire passage showed synthetic speech to be disadvantaged only in the case of nonpracticed listeners. Again, minimal practice with synthetic speech dispelled the differences.