Nonsense Utterances Research Articles

Peak magnitudes of supraglottal air pressure associated with affricated and nonaffricated stop consonant productions in Hindi

Peak magnitudes of supraglottal air pressure, under a variety of conditions, were obtained during stop productions from three normal adult speakers of Hindi. The stops were produced in CVCVC nonsense utterances which were embedded in the carrier phrase, “ye—hae.” Significant differences in peak magnitudes were found as a function of the place of articulation of a stop and its position in an utterance. Peak magnitudes were always significantly higher for unvoiced stops than for voiced stops. Aspirated stops, in general, showed higher peak magnitudes than unaspirated stops, but a significant level of difference in peak magnitudes was reached only under voiced conditions. Differences in peak magnitudes as a function of stress were significant under voiced conditions; under unvoiced conditions the differences were less pronounced.

The effect of position in utterance on speech segment duration in English.

The duration of speech segments as a function of position in utterances (initial, medial, final) was studied. In the first experiment seven English speakers read nonsense utterances of the form “say a [bab], say a [bábab], say a [babáb],” etc. Spectrograms were used to determine the duration of speech segments in the readings. Final syllables were found to be longer than nonfinal syllables. Final-syllable vowel increments were approximately 100 msec. Final-syllable consonant increments were less than vowel increments; for instance, absolute final consonant increments were about 20 msec. Also word-initial consonants were found to be lengthened by 20–30 msec over medial consonants. Subsequent experimentation demonstrated with English nonsense words that (1) final-syllable and initial-consonant lengthening occur in utterances with various intonational patterns (imperative, declarative, interrogative); (2) final-syllable lengthening occurs in word-final and phrase-final positions as well as in utterance-final position; and (3) final-syllable and initial-consonant lengthening occur in various kinds of syllables, including syllables with diphthongs, with fricative consonants, with voiceless stops, with consonant cluster, and with no final consonants (i.e., CV syllables). These studies report durational increments of particularly great magnitude for absolute final fricative consonants. Explanations of the lengthening effects are discussed. One theory suggests that lengthening in certain utterance positions is a learned aspect of language which cues listeners concerning the location of boundaries of words, phrases, or sentences. Explanations based on hypothesized properties of the speech production process are also discussed.

Dynamic Behavior of the Hyoid Bone, Mandible, Tongue, and Thyroid Cartilage During Speech Production

Using lateral-view cinettuorographic techniques, movement activities of the hyoid bone, mandible, tongue, and thyroid cartilage were observed. The speakers read 18 CVCV nonsense utterances imbedded in a carrier phrase. A stressed-unstressed/unstressed-stressed paradigm was employed within this disyllable utterance. Using a computerized frame-by-frame analysis technique [provided by the Speech Communications Research Laboratory, Inc., Santa Barbara, Calif.], movement characteristics were retrieved separately for the vertical and horizontal displacement components of each structure. From the retrieved data separate linear displacement plots for each structural component were produced as a function of time. The relations among simultaneous movements of the mandible, tongue, thyroid cartilage, and hyoid bone during productions of the vowels /i, a, u/ are reported as a function of adjacent consonant and syllable stress.

Syllable Structure and Sentence Rhythm—A Cross Language Study

Differences in segmental structure between English, French, and Polish were examined to determine the effect of this structure on perceived rhythm. In conversational French the sequence VC♯CV́ is uttered as V♯CCV́; these sequences are not homophonous in English or Polish. Assuming that the rhythmic character of the second syllable of such a sequence depends very little upon segments preceding the juncture, then VC♯CV́ and V♯CCV́ should appear rhythmically similar in French but different in both English and Polish, whereas V♯CV́ and VC♯CV́ should be similar in both English and Polish, but different in French. Nonsense utterances containing VC♯CV́, V♯CCV́, and V♯CV́ sequences were produced by native English, French, and Polish speakers; other native speakers judged the rhythms of these utterances by tapping their fingers in time to the stressed syllables. Preliminary data suggest that (1) listeners “hear” the rhythm of an utterance more clearly when it is spoken by a compatriot than by a foreigner, and (2) listeners tend to perceive rhythmic structure in terms of their own linguistic rules, regardless of the language of the utterance.

Position-in-Utterance Duration Effects

The duration of speech segments as a function of position in utterances (initial, medial, final) was studied. Seven English speakers read nonsense utterances of the form “say a bab, say a babab, say a babab,” etc. Spectrograms were used to determine the duration of speech segments in the readings. Final syllables were found to be longer than nonfinal syllables. Final-syllable vowel increments were about 100 msec. Final-syllable consonant increments were less than vowel increments, for instance, 20 msec for absolute final consonants. Also word-initial consonants were found to be lengthened by 20–30 msec. It is suggested that durational studies in general should be interpreted in the light of findings concerning position-in-utterance lengthening. Explanations of lengthening effects are discussed. One theory suggests that lengthening in certain utterance positions is a learned aspect of languages which cues listeners concerning the segmentation of utterances into words, phrases, or sentences. Explanations based on hypothesized properties of the articulatory control system are also discussed.

Relative Perceptual Cue Strength for Voiced Stop Consonants

The relative strength of noise bursts and vocalic transitions as perception cues of word initial voiced stop consonants in CVC nonsense utterances was investigated using a tape splicing technique. All possible combinations of noise bursts and vocalic transitions in CVC utterances (using /b, d, g/ as initial consonants, /i, æ, a, u/ as vowel, and /z/ as the final consonant) were obtained by tape splicing-substitution techniques. Temporal segmentation was accomplished by inserting a piece of splicing tape before each utterance. A sonogram was made on which the location of the tape splice in relation to the utterance was shown. Measurement of the sonogram and conversion to distance along the tape allowed for a precise tape splice for substitutions of noise bursts and vocalic transitions (cue switching). The first 10 msec of noise burst and the following 50 msec vocalic transition were systematically substituted for presentation to a group of listeners. For example, each listener heard /biz/ produced in a normal manner, a silence inserted for the /b/ burst plus /iz/, and /b/ burst attached to all combinations of /iz/ which originally had been produced with either /d/ or /g/ as the initial consonant. Similiarly vocalic transitions were varied, so that each transition was substituted into all other CVC utterances. The results of this investigation indicate a slight preference for listeners to identify CVC syllables on the basis of the noise burst rather than on the basis of the transitional information.

Supraglottal air pressure in the production of English stops.

Generally higher levels of intra-oral air pressure during occlusion are regularly reported for English /p,t,k/ as compared with /b,d,g/, and considerable significance has been attached to such observations, particularly by phonologists. Many of the published bodies of data, however, represent quite limited speech samples, consisting in the main of short nonsense utterances which contain stops in only a few contextual situations. In the present study ten readings of a list of twenty short English phrases were recorded for a single speaker. The phrases contained stops in initial, medial and final positions, and under various conditions of stress. A pressure transducer mounted at the end of a nasal catheter was introduced into the pharynx, and variations in intra-oral pressure were recorded on a multi-channel penwriter. From the pressure records obtained it appeared that /p,t,k/ and /b,d,g/ differ in their mean peak pressures, but that this difference is not equally significant in all contexts. Both initially and medially before a stressed vowel the two categories show peak pressures that overlap very extensively. This makes questionable the view that such differences more regularly co-exist with the /p,t,k/:/b,d,g/ distinction than any difference in voicing or mode of laryngeal operation, and that they demonstrate the " fortis ":" lenis " nature of the distinction.

Fricative and plosive perception-identification as a function of phonetic context in CVCVC utterance.

Hypothesis: The largest perceptual influence unit (PIU) for consonant perception-identification is of larger than syllable size and at least of the size CVCVC. The PIU is defined as that number of two or more successive speech sounds which influence the perception-identification of a given sound within that sequence. Each of twenty listeners attempted to identify the centrally occurring consonant /p t k b d g f s ∫ v z / in each of 576 CVCVC nonsense utterances occurring in white noise. The vowel context included combinations of /i α u/ while the outside consonants were both either /θ/ or /m/. Results indicated that plosive and non-sibilant fricative intelligibility varied significantly as a function of trans-consonantal vowel interaction (V C V). Furthermore trans-vowel consonant influence (C V C and/or C V C) significantly affected the intelligibility of almost all of the stimulus sounds. This latter finding, considered together with the former, clearly supports the proposed hypothesis.

On Vowel Duration in English

Average durations of 12 vowels of American English measured in bisyllabic nonsense utterances are reported. The vowels occurred in 14 symmetrical consonantal environments and the utterances were produced by three male talkers. The consonant environments consisted of the voiced and voiceless versions of three stop, one affricate, and three fricative consonant articulations. Four determinants of the characteristic durations of stressed vowels are identified and discussed. The hypothesis is advanced that the primary lengthening of vowels in English—that found in tense vowels and in vowels before voiced constants—is a part of the phonology of the language and is learned by speakers of the language, and that the secondary lengthening of vowels in English—that found in open vowels and in vowels before fricative constants—is a function of the articulatory process itself.

Automatic Measurement of the Formants of Vowels in Diverse Consonantal Environments

The principle of analysis-by-synthesis, described in earlier papers, is applied to the measurement of the formant frequencies of the common vowels of American English. The vowels measured constitute segments of bisyllabic nonsense utterances recorded by three adult male talkers. The set of materials is designed to provide samples of stressed vowels preceded and followed by a variety of consonants. The vowels in question occur in consonant-vowel-consonant syllables in which both consonants represent the same phoneme of American English. Frequencies of the first three formants are measured throughout the vowel for spectral samples separated by approximately 8 msec. Effects on formant frequencies attributable to temporal location of sample, consonant environment, and individual talkers are discussed. For central locations of the samples, the formant frequencies differ systematically from published data derived from more restricted consonantal environments. Phenomena relating to formant transitions and individual talker characteristics are discussed. [This work was supported in part by the U. S. Army (Signal Corps), the U. S. Air Force (Office of Scientific Research, Air Research and Development Command), and the U. S. Navy (Office of Naval Research); and in part by the Air Force Cambridge Research Center.]