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The focus of the research conducted in the Speech Perception Assessment Laboratory is the accurate assessment of speech perception by individuals with normal hearing and individuals with hearing impairment. The tools and procedures used to assess speech perception are evaluated for their validity and reliability in various listening situations. This research is directed by Dr. Lisa Lucks Mendel who is an Associate Professor in the School of Audiology and Speech-Language Pathology and co-author of the textbook Audiologic Assessment and Management and Speech Perception Assessment. |
Research in the Speech Perception
Assessment Laboratory is currently focused on the following projects:
(1) Validation of subjective
self-assessment outcome measures with objective speech perception performance
scores:
The purpose of this study it to validate
the use of specific speech recognition assessment materials as an objective
means for documenting improvements in speech understanding with hearing
aids. Patients often complain that they have considerable difficulty understanding
speech as a result of their hearing loss; this is particularly true in
a background of noise. Recent advancements and improvements in hearing
aid technology appear to have minimized this difficulty as evidenced by
the subjective reports provided by many self-assessment hearing aid outcome
measures. However, a need exists to document objectively the improvement
that hearing aid wearers experience in their speech perception performance.
Traditional speech recognition tests have long been criticized for not
being sensitive enough to provide this information. Unfortunately, this
has led many audiologists to avoid administering any form of speech recognition
testing as part of a hearing aid evaluation.
In this study, speech perception
performance scores (Speech Perception in Noise (SPIN Test), Speech in Noise
(SIN) Test, and the Hearing in Noise Test (HINT)) are being compared with
subjective self-assessment outcome measures (Abbreviated Profile of Hearing
Aid Benefit (APHAB)) to confirm improvements in performance. Both speech
recognition testing and outcome measures are being administered to new
hearing aid wearers prior to hearing aid fitting, 30 days post hearing
aid fitting, and 60 days post hearing aid fitting. Speech recognition scores
are then being correlated with scores on specific questions of the APHAB
that deal with the subject’s perception of speech in quiet and noisy backgrounds.
Objective documentation that speech recognition tests correlate highly
with hearing aid outcome measures will strengthen the need for such measures
to be included as an integral part of a hearing aid evaluation.
(2) Validation of actual
and predicted word recognition scores for listeners with hearing impairment:
In this retrospective study, records
of veterans who had audiological compensation and pension examinations
(hearing evaluations) at the Veterans Administration Medical Center (VAMC)
in Jackson, Mississippi between 1992 and 2001 are being reviewed. Audiologists
are often called upon to decide whether a given word recognition score
is in line with what is expected from a patient with a given degree of
hearing loss. Comparison of actual scores with expected or predicted scores
has diagnostic and rehabilitative implications as well as information for
judging the validity of the obtained score and the accompanying pure tone
thresholds. However, there is currently no objective and quantitative methodology
in widespread use for evaluating word recognition scores. Therefore, the
purpose of this study is to establish an objective method to assist the
audiologist in assessing the word recognition score obtained as part of
a hearing evaluation. This is being done by reviewing clinical records
from the VAMC and establishing confidence limits for representative scores.
In addition, the articulation index is being calculated to determine the
prediction of audibility. It is hoped that by using these methods the accuracy
and validity of word recognition scores obtained from pervious evaluations
can be established.
(3) Effectiveness of sound
field FM amplification in elementary school classrooms:
Sound field FM amplification is a
recognized strategy for reducing the detrimental effects of poor classroom
acoustics that are often found in schools providing elementary education
to children with normal hearing. The purpose of this study is to determine
the effectiveness of using sound field FM amplification systems over a
two-year period at an elementary school in North Mississippi beginning
with kindergarten and ending in first grade. Half of the classrooms comprise
the experimental group and have sound field amplification systems installed
in them. The remaining classrooms serve as the control group and do not
have access to sound field amplification. All classrooms are similar in
their shape, size, and acoustic characteristics. The teachers in the experimental
classrooms wear the FM microphone/transmitter throughout the day when doing
group instruction.
Four areas of performance comprise
the efficacy measurements in this study: (1) achievement test scores, (2)
phonological awareness, (3) localization ability, and (4) speech perception
in noise. Preliminary analysis of the data collected reveals no significant
differences between the experimental and control groups for tests of achievement,
phonological awareness, or localization ability. No significant differences
were measured on the speech perception task using the PBK word lists or
on the WIPI when no FM amplification was used. However, one significant
difference has been measured so far in the baseline data. The students
in the experimental group performed significantly better on the WIPI when
it was presented through the sound field amplification system than without
it. This finding suggests that there is an immediate objectively measurable
benefit observed from using sound field FM amplification in elementary
classrooms that does not require extensive exposure to it use. After one
year, the experimental group is beginning to demonstrate improvements in
phonological awareness, achievement test scores, and localization ability.
Further significant improvements are expected by the end of this two-year
study.
(4) Speech intelligibility
and hearing function in Navy Divers:
Previously, Dr. Lucks Mendel served
as Associate Director for the Center for Speech and Hearing Research in
the National Center for Physical Acoustics at the University of Mississippi.
During that time, she received over $500,000 of external funding to conduct
research with Navy divers at the Navy Experimental Diving Unit in Panama
City, Florida. These research projects focused primarily on studying changes
in hearing physiology that occurred when Navy divers were at depth. In
addition, studies were conducted that focused on developing ways to improve
speech intelligibility and speech perception among divers who work in noisy
environments under adverse conditions. Because Navy divers work at such
deep depths and must breathe helium, the quality and intelligibility
of their speech is affected. A related project focused on analyzing the
acoustic characteristics of the helium speech that was produced. The effects
of helium and pressure changes on speech production and perception were
studied in order to make improvements in the communication systems used
by these divers.
Mendel, L.L., Danhauer, J.L., &
Singh, S. (1999).
Singular’s Pocket Dictionary of Audiology. San
Diego, CA: Singular Publishing Company, Inc.
Mendel, L.L. and Danhauer, J.L.
(1996). Audiologic Evaluation and Management and Speech Perception Assessment.
San Diego, CA: Singular Publishing Company, Inc.
Mendel, L.L. (1996).
Professional education and provider competence. In D. Zapala &
L. L. Mendel (Eds.), Seminars in Hearing, Hearing Care Service Delivery:
Essays and Articles, Vol.17, No.3, pp. 297-304.
Zapala, D.A. & Mendel, L.L. (Eds.)
(1996). Seminars in Hearing, Hearing Care Service Delivery: Essays
and Articles, Vol.17, No.3. Monograph.
English, K. E., Mendel, L. L., Rojeski,
T., & Hornak, J. (1999). Counseling in Audiology, or Learning to Listen:
Pre- and Post-Measures from a Counseling Class in an Audiology Doctorate
Program.
American Journal of Audiology, Vol. 8, No. 1, pp. 34-39.
Mendel, L. L., Hamill, B. W., Hendrix,
J. E., Crepeau, L. J., Pelton, J. D., Miley, M. D., & Kadlec, E. E.
(1998). Speech Intelligibility Assessment in a Helium Environment - II:
The Speech Intelligibility Index. Journal of the Acoustical Society
of America, 104, 1609-1615.
Mendel, L.L., Wynne, M.K., English,
K., & Troike, A. (1995) . Computer applications in educational
audiology. Language, Speech, and Hearing Services in the Schools,
26, 232-240.
Mendel, L.L., Hamill, B.W., Crepeau,
L., & Fallon, E. (1995). Speech intelligibility assessment in
a helium environment. Journal of the Acoustical Society of America,
97 (1), 628-636.
Culpepper, N.B., Mendel, L.L., &
McCarthy, P.A. (1994). Counseling experience and training offered by ESB-Accredited
programs: An update. Asha, 36, 6, 55-58.
Mendel, M.I. & Mendel, L.L.
(1993). Successful recruiting strategies. Asha, 35,
8, 41-42.
Mendel, L. L., & Danhauer, J.
L. (1991). Stimulus presentation level and speech perception
through a single-channel cochlear implant. Journal of the American
Academy of Audiology, 2, 226-236.
Danhauer, J. L., Ghadialy, F. B.,
Eskwitt, D. E., & Mendel, L. L. (1990). Performance of
3M/House cochlear implant users on tests of speech perception. Journal
of the American Academy of Audiology, 1, 236-239.
Doyle, P.C., Danhauer, J.L., &
Mendel, L.L. (1990). A SINDSCAL analysis of perceptual features
for consonants produced by Esophageal and Tracheoesophageal Talkers.
Journal
of Speech and Hearing Disorders, 55, 756-760.
Danhauer, J. L., Ghadialy, F. B.,
Beck, D. L., Lucks, L. E., & Cudahy, E. A. (1990). Audio-visual
consonant recognition with the 3M/House cochlear implant. Journal
of Rehabilitative Research and Development, 27, 247-254.
Danhauer, J. L., Beck, D. L., Lucks,
L. E., & Ghadialy, F. B. (1988). A sentence test for audiologic
assessments of severe and profound losses. The Hearing Journal,
7, 26-33.
Danhauer, J. L., & Lucks, L.
E. (1987). The confusion matrix: A new model. Human
Communication Canada, 11, 7-11.
Danhauer, J. L., Doyle, P. C., &
Lucks, L. E. (1986). Effects of signal-to-noise ratio on the nonsense
syllable test. Ear and Hearing, 7, 323-324.
McCarthy, P. A., Culpepper, N. B.,
& Lucks, L. E. (1986). Variability in counseling experiences and training
among ESB-accredited programs. Asha, 9, 49-52.
Danhauer, J. L., Lucks, L. E., &
Abdala, C. (1986). Survey of speech perception assessment materials
used by cochlear implant centers. Journal of Auditory Research,
26, 75-87
Beck, D. L., Danhauer, J. L., Cudahy,
E. A., & Lucks, L. E. (1986). Evaluation of cochlear implants:
Toward a national cochlear implant study. The Hearing Journal,
6, 17-18.
Danhauer, J. L., Doyle, P. C., &
Lucks, L. E. (1985). Effects of noise on NST and NU-6 stimuli.
Ear
and Hearing, 6, 266-269.
Mendel, L.L., Danhauer, J.L., &
Singh, S. (1999).
Singular’s Illustrated Dictionary of Audiology.
San Diego, CA: Singular Publishing Company, Inc. Textbook and CD-ROM.
Mendel, L.L. (1996). Children
and Adolescents with Hearing-Impairment and Their Parents. In T. A. Crowe
(Ed.), Applications of Counseling in Speech-Language Pathology and Audiology.
Baltimore, MD: Williams & Wilkins, pp. 290-306.
Mendel, L.L., Knafelc, M.E, &
Cudahy, E.A. (2000). Hearing Function in a Hyperbaric Environment. Undersea
and Hyperbaric Medicine, Vol. 27, No. 2, pp. 91-105.
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