SHHH Research Symposium
Matthew Bakke Ph.D. and Harry Levvit Ph.D. of Gallaudet University
presented an overview of current research at the Rehabilitation
Engineering Research Center (RERC) on Hearing Enhancement.
Dr. Bakke first presented some of their goals, which included:
- Technical solutions to problems of people with hearing loss
- Exchange of technical and engineering information
- Improve the distribution of equipment to people with hearing loss.
Recent hearing aid work at the RERC has focused on two issues:
- Evaluation of two different methods (NAL-NLI and VIOLA) of fitting
multi-channel compression hearing aids. They have verified that the two
methods produce different results, but have not yet formed conclusions
regarding which method provides better hearing.
- Evaluation of hearing aids with multiple microphones. This includes
relatively simple two-microphone systems as well as more complex
beamforming arrays with up to five microphones. The studies are
considering the effect of multiple microphones on sound localization and
directionality. While directionality seems to improve understanding in
certain situations, it may have adverse effects on sound localization.
A final comment regarding hearing aids is that hearing aid
specifications don't match what they are finding regarding hearing aid
performance on people's heads.
RERC also has a program to evaluate hearing assistance technology.
This program focuses on directionality and on the interaction between
wireless phones and hearing aids.
The RERC Training and Technical Assistance program includes a
collaborative effort with SHHH to train audiologists and organization
leaders.
Dr. Harry Levvit continued the presentation of the RERC research
efforts.
He began with a synopsis of the RERC research regarding tinnitus. He
emphasized that there is currently very little in the way of treatment,
and that their research is focusing on providing treatment. They are
working on subjective and objective measures of tinnitus. One effort
with the League of Hard of Hearing in New York is focusing on Tinnitus
Habituation Therapy (THT). These results are interesting, because 80% of
patients report improvement following THT, but objective measures don't
show any improvement.
Dr. Levitt then briefly mentioned current development areas,
including an analysis of the effects of electromagnetic interference on
hearing equipment, and an analysis of the acoustic properties of public
address (PA) systems.
The RERC is also working on automatic speech recognition (ASR). Their
current efforts are focusing on the critical variables that affect
understanding and on developing an interface for the use of ASR to
provide remote CART.
Future research directions include:
- Compression and directinality in hearing aids
- Hearing aid fitting procedures
- Automatic control of hearing aids vice manual control
- Background noise reduction, including the application of
directionality, the automatic detection and suppression of noise, and
binaural processing
- The application of wireless communications protocols, including
Bluetooth, to assistive listening devices (ALDs)
- Cochlear implants (CIs), including bilateral CIs and better speech
processing strategies.
Q: You mentioned objective measures of tinnitus. What measures are
you using?
A: We're focusing on otoacoustic emissions, which seem to be closely
related to tinnitus.
Q: How will Bluetooth be used with ALDs?
A: Well, it won't be used in the near future, because of the current
high power requirements. But we project that wireless communications
technologies like Bluetooth will eventually be able to replace the
telecoil.
Q: I had tinnitus for 20 years; then I got a cochlear implant (CI)
and the tinnitus went away. Is that normal?
A: It's certainly not uncommon. We think the reason for this is that the
CI bypasses the cochlea, which is where we think tinnitus originates.
For more information, visit the RERC website at
www.hearingresearch.org. Many of the RERC publications are available on
this site.
Dr. Carren Stika of the Rehabilitation Research and Training Center (RRTC)
for Persons who are Hard of Hearing or Late Deafened presented the
results of RRTC's recent research into employment and personal
adjustment issues. Carren began with several facts regarding their
research area.
- Hearing loss is one of the most common physical conditions, but there
is relatively little research on its psychosocial aspects
- Most of the research that is available is in audiology journals rather
than psychology journals, which means that it's not getting attention
from psychologists
- Psychologists tend to lump Deaf and hard of hearing people together
- Little attention has been paid to the effect of hearing loss on
employment, but 60% of people with hearing loss are between the ages of
40 and 60.
- There has been considerable effort to prevent hearing loss, but very
little to help people who suffer from it.
RRTC is working to correct these situations. They have been involved
in a total of 18 broad studies involving hard of hearing people and
their families. Their initial studies focused on SHHH members, but
critics rightfully commented that SHHH members are the "elite"
of the hard of hearing population and that their results are not typical
of the "average" hard of hearing person.
So subsequent studies were focused more on the "average"
hard of hearing person. These studies had 400 participants, of which 43
used cochlear implants (CIs). These people responded to a battery of
questionnaires, and also provided about 500 pages of single-spaced
comments, which the folks at RRTC are currently transcribing.
The National Council on Aging has done studies on the benefits of
hearing aids, and found that people who use hearing aids report a much
better quality of life than those who don't. Other studies have shown
that, on four of six criteria (physical, psychological, independence,
and social), people with CIs report the same quality of life as people
with normal hearing, while hearing aid users report a lower quality of
life.
Among the SHHH study participants, many people refrain from telling
their employers and coworkers about their hearing loss, because they
fear dismissal, stigmatization, loss of advancement, and being viewed as
less capable. They also reported not knowing whether to reveal their
hearing loss during the interview process, and if they chose to reveal
it, when they should do so.
Of the 400 participants in the broader study, 29% did not tell their
employer about their hearing loss.
Do people with hearing loss request appropriate accommodations at
work? Many of the SHHH respondents reported that they did not ask for
accommodations, because they feared being viewed as different and they
didn't know who should provide the required equipment.
Of the participants in the broader study, 37% reported that they
rarely or never asked for accommodations, even free and simple
accommodations like changing people's seating locations. When asked the
reason they failed to request accommodations, a few people replied with
these answers: I wouldn't get it if I asked, it's too expensive, it
would jeopardize advancement, my coworkers would resent it, and my
employer would resent it. More popular responses included:
- Others will think less of me (46% of subjects under age 40, 25% of
subjects over age 40)
- I would be embarrassed (51%, 25%)
- I don't want to draw attention to myself (49%, 39%)
When asked if they thought that hearing loss prevents promotion
opportunities, 49% replied, "Yes". Further analysis reveals
that this perception can be "employer-driven" or
"employee-driven", and that the "employee-driven"
perception is more prevalent. This means that the people with hearing
loss are more likely to question their capabilities than their boss or
coworkers.
People also said that they were anxious about the prospects of
changing bosses or jobs. Some stay in their current position because
they are anxious about the interview process. Altogether, fully half of
respondents reported that they have not left or changed jobs because of
their hearing loss.
Comment from the audience: In addition to my job handling my job
requirements, I also have to be a hearing loss expert and I have to
always plan how I'll be able to communicate. It's really like having
three jobs!
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