The time course of vowel context effects

The time course of vowel context effectsHoward C... The time course of vowel context effects.. Sawusch Department of Psychology, State University of New York at Buffalo, Amherst, NY 142

The time course of vowel context effects

Howard C Nusbaum and James Sawusch

Citation: The Journal of the Acoustical Society of America 67, S53 (1980); doi: 10.1121/1.2018271

View online: https://doi.org/10.1121/1.2018271

View Table of Contents: https://asa.scitation.org/toc/jas/67/S1

Published by the Acoustical Society of America

peak glottal opening during the devoiced vowel is larger when a

fricative either precedes or follows it, and smaller when the vowel is

surrounded on both sides by single or geminated stops [Work

supported by NINCDS and BRSG.]

a) Also: University of Tokyo, Japan

b) Also: Lund University, Sweden

4:48

V15 Scaling of glottal opening A L6fqvist, a) T Baer, and H

Yoshioka b) (Haskins Laboratories, 270 Crown Street, New Haven,

CT 06510)

Laryngeal control mainly occurs along two dimensions One

involves the longitudinal tension of the vocal cords and is used for

F0 control Speakers can normally exert very fine-graded control in

this dimension, and it is used extensively for linguistic purposes The

other dimension is that of abduction-adduction, involved in the

control of phonation type, voicing, and aspiration From published

records, it appears that more than two or three distinct degrees of

glottal opening are rarely used during speech production in different

languages The present experiment was designed to clarify the

control of glottal abduction-adduction and examines how many

degrees of glottal opening speakers can produce consistently under

various static and dynamic nonspeech and speech conditions

Glottal opening was monitored simultaneously by a fiberscope and a

transillumination system Preliminary results indicate that without

training and visual feedback subjects can only produce gross

abduction and adduction gestures and are unable to make finely

controlled variations of glottal opening [Work supported by NINCDS and BRSG.]

a) Also: Lund University, Lund, Sweden

b) Also: University of Tokyo, Tokyo, Japan

5:00

V16 The time course of vowel context effects Howard C Nusbaum

and James R Sawusch (Department of Psychology, State University

of New York at Buffalo, Amherst, NY 14226)

At previous meetings of the Society we presented evidence for the existence of two different perceptual mechanisms mediating anchor-

induced contrast effects found with vowels Extra presentations of an [i] endpoint to subjects identifying an [i]-[I] series caused changes

in sensitivity Anchoring with [I] produced criterion shifts which

were dependent on the availability of auditory memory Since

[i] and [I] differ in tenseness, intrinsic duration in natural speech, and acoustic status (point versus nonpoint), the differences in perceptual effects of these vowels cannot be ascribed to any one factor To explore the role of these variables in vowel context effects, a number of different vowel series from different parts of the vowel space have been examined using a successive contrast paradigm In this procedure, a context vowel is presented first, followed at varying temporal intervals by a test vowel Results

obtained using this procedure provide new evidence concerning the

perceptual mechanisms underlying vowel anchor effects Further, the pattern of these results obtained with different vowel series have important implications for theories of vowel perception [Work supported by NSF and NIMH.]

THURSDAY MORNING, 24 APRIL 1980 BALLROOM SOUTH, 9:00 A.M TO 12:00 NOON

Session W Noise V: Vehicle Noise and Noise Propagation

Robert D Bruce, Chairman

Bolt Beranek and Newman Inc., 50 Moulton Street, Cambridge, Massachusetts 02138

Contributed Papers

9:00

W1 Urban light motor vehicle noise levels at close-in distances for a

worst case situation Gale R Hruska (U.S Environmental Protection

Agency, Region V Noise Program, 230 S Dearborn Street, Chicago,

IL 60604) and Kent C Williams (U.S Environmental Protection

Agency, Region IV Noise Program, 354 Courtland Street, N.E.,

Atlanta, GA 30308)

Effective motor vehicle noise enforcement in many urban areas can

only be accomplished if measurements are made relatively close to

the vehicle To help define reasonable enforcement levels, in situ

sound level measurements were recorded in four geographical loca-

tions for 8307 light weight motor vehicles accelerating from rest or

near rest To insure a "worst case" situation, the microphones were

positioned at 3.81 m from the centerline of travel and 27 to 46 m

from the initial point of acceleration The data were partitioned into

three "acceptable" vehicle classes and one class which included all

vehicles judged to have had defective or modified exhaust systems,

or had been unreasonably driven Analysis of the data shows that the

"unacceptable" vehicle distribution has a mean sound level at least

6 dBA greater than those obtained for all of the "acceptable" classes Relations between the posted speed limits and the mean

values of the observed sound levels were obtained

9:15

W2 Vehicle passby sound level time histories J S Bradley (Faculty

of Engineering Science, University of Western Ontario, London,

Ontario, Canada N6A 5B9)

An earlier study of particular vehicles of various types [ J S Bradley, J Acoust Soc Am Suppl 1 65, S66 (1979)], indicated

that vehicles are directional radiators of sound in the horizontal

plane and that the assumption of a point source was incorrect The present investigation extended the work to include an analysis of a large number of vehicle passby time histories for various vehicle types to determine how representative the particular results were Average passby time histories were computed for five different vehicle classifications and compared to predicted values Results showed deviations from a point source model and varied with vehicle

$53 J Acoust Soc Am Suppl 1, Vol 67, Spring 1980 99th Meeting: Acoustical Society of America $53