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Biomedical subjects

N J Lass

Publications and source records attributed to N J Lass.

At least 55 records · Page 3Linked to original sources
PubMed1978

Spectrographic analysis of laryngeal air sac resonance in rhesus monkey.

Laryngeal air sacs are circular out-pocketings, located in the hyoid bone with their ostium in the midline of the anterior part of the larynx. From previous cadaver studies of the rhesus monkey it was deduced that the function of the air sac is to act as a resonating chamber. The present study was designed to test this hypothesis. Recordings were made of three rhesus monkeys before and after surgical removal of the air sac. Spectrographic analysis of the monkeys' vocalizations indicated that differences in formant frequency characteristics between pre-and post-surgical recordings were negligible. This finding suggests that the laryngeal air sac does not play an important role in the resonant properties of the monkeys' vocal tracts.

Animals↗
PubMed1978

Correlational study of speakers' heights, weights, body surface areas, and speaking fundamental frequencies.

The purpose of this investigation was to determine the relationship among speakers' heights, weights, body surface areas, and speaking fundamental frequencies. The recordings of 30 speakers' readings of a standard prose passage were analyzed by means of the Fundamental Frequency Indicator (FFI) to obtain their speaking fundamental frequency characteristics. The speakers' heights and weights were obtained by means of standard measurement procuedures, and their body surface areas were calculated. Pearson product-moment correlation coefficients, computed separately for men and women, indicated that speakers' heights, weights, and body surface areas were not significantly correlated with their speaking fundamental frequencies; female speakers showed a slight negative correlation while male speakers showed a low, positive trend. Implications of these findings and suggestions for future research are discussed.

Body Height↗
PubMed1978

A comparative study of the effect of two time-alteration techniques on listener comprehension.

The purpose of this investigation was to determine if listener comprehension is differentially affected by two different techniques of time alteration: the sampling method and the harmonic compression method. The Nelson-Denny Reading Test, consisting of 8 selections of scientific and literary content appropriate for college students with respect to interest and level of difficulty, was presented to 3 groups of 40 Ss each; each group was given the tape-recorded test after processing at one of the 3 speech rates, normal, half normal, or twice normal rate. Of the 8 selections on this test, 4 were processed by sampling using a VARISPEECH-I compressor/expander, and 4 were processed by harmonic compression using a Lockheed LM-312 Pitch Normalizer. There were of course some differences in listener comprehension as a function of rate, but within each of the rate conditions there were no significant differences as a function of method of time alteration. With the type of speech material used here, and within these rate conditions, these time alteration methods can be used interchangeably in such research.

Adolescent↗
PubMed1977

Articulation improvement and oral tactile changes in children.

To determine whether oral tactile changes accompany improvement in articulation, 16 children were administered two tests of oral tactile perception and two tests of articulation competency at three time periods: before, during, and at the end of speech therapy. A positive relationship between articulation proficiency and oral tactile perception was established. Both articulation tests reflected a progressive improvement for the group across the three testing periods. One of the tests of oral tactile perception reflected the same progressive trend and the second test, while not exhibiting the identical trend, did reflect a general improvement from the first to the third testing period. These findings indicate that oral tactile skills appear to be important factors in speech production and that such skills should be assessed in cases of functional articulation disorders,

Child↗
PubMed1976

The use of time-expanded speech as an aid in the diagnosis of articulation disorders.

The recordings of 20 speech defective speakers' readings of a standard prose passage were presented to 36 student speech clinicians under three listening conditions: (1) unaltered; (2) time expanded to 150% of the original recording time; and (3) time-expanded to 200% of the original recording time. Results of their evaluations indicate that the expanded versions of the recordings elicited more accurate evaluations by the student clinicians. Implications of these findings concerning the possible usefulness of time-expanded speech as an aid in the training of listening skills in student speech clinicians are discussed.

Adult↗
PubMed1975

Clinician bias: the effects of pretesting information on the evaluations of speech clinicians.

The purpose of this investigation was to determine if pretesting information has a biasing effect on the speech evaluations of student speech clinicians. A total of three groups of clinicians evaluated 10 speech characteristics of each of 17 recorded speech samples. The clinicians participated in two listening sessions. In the first (control) session, they evaluated the speech samples using a 4-point scale of defectiveness and were given no background information on the speakers. In the second (experimental) session, they were given fabricated case history information prior to their evaluations. Results of their ratings indicate that the pretesting information had a biasing effect on the clinicians' evaluations of the speech samples. Implications of these findings and suggestions for future inquiry are discussed.

Adolescent↗
PubMed1975

A normative study of children's performance on the short form of the Token Test.

Spellacy and Spreen's Short Form of the Token Test was administered to 240 normal middle-class children, 20 in each of 12 half-year age groups from 6.0-6.5 through 11.6-11.11. Results of their performance on this test indicate that there are only slight differences between any of the 12 age groups investigated. The findings of this investigation provide normative data on children's performance on the Short Form of the Token Test, information that should be very useful in screening procedures for assessment of receptive language skills in children.

Child↗