Student-designed testing system to aid hearing research
(Top photo) Sofie Ganev, Tony Battu, Michael Kessler and Brian Allen test the system. (Middle photo) Jonathan Smith (left), Brandon Lancaster and Brittany Harwell discuss the data. (Bottom photo) The team discusses progress of the hearing test system that patients will set up and use themselves.
How would your life be different if you could hear out of
just one ear?
How would your life change if surgery suddenly allowed you
to hear out of both ears after having spent a significant part of your life
only able to hear out of one?
JMU researcher Dr. Lincoln Gray has spent a good bit of his
career investigating the answers to those two questions, and now his research
could be on the verge of a breakthrough with help from a device being designed
and built by a group of JMU students.
The student group includes four senior engineering majors and
two junior engineering majors advised by Dr. Robert Nagel, an assistant
professor of engineering. Also part of the team is a senior communication
sciences and disorders major being advised by Gray. The team will give a
presentation on the device, a distributable hearing test, during the 2013
Engineering Poster Fair from 2-5 p.m. April 19 in the Rose Library flex space.
The system is being designed to evaluate and collect data
from patients who have had surgery to correct congenital aural atresia, a
condition caused by a deformed external auditory canal. "The auditory
receptor, the part that does the work of sending those sound messages to the
brain is intact and ready to go, it just doesn't get any sound in," said
Gray, a professor of communication sciences and disorders.
Surgery can correct the problem and no
one does more surgery on aural atresia patients than Gray's colleague at the
University of Virginia Medical Center, Dr. Bradley Kesser. Gray and Kesser know
the surgery has some short-term benefits, but they lack data on most patients
after their first follow-up visit. "I've never been able to follow them up
basically more than a month because the insurance companies will only pay for
them to come back to U.Va. for the one-month post-op visit, and that's when Dr.
Kesser pulls the packing out of their ear and basically they hear for the first
time," Gray said.
Because many of Kesser's patients come from across the
country as well as from other countries, getting them to come back for further
testing and study is cost-prohibitive in most cases. The hearing test system is
being designed so it can be shipped to patients, who will be able to do the
tests themselves and then return the device and the data. The system consists
of a laptop computer; eight speakers; a mat on which the system is set up; custom
software; instructions for setting up and using the system; and the packaging.
"I don't think there's a machine
like this out there yet that specifically localizes sound and that you can do
yourself," said Sofie Ganev, the communication sciences and disorders major.
Ganev is using test results from the system for her honors thesis.
Brandon Lancaster, one of the four
senior engineering majors and the team leader, said, "I think everyone's
had the experience of going to the doctor and putting on the headphones with
the pure-tones and then you raise your hand if you hear the tone. So that's an
example of an audio test that determines your pure-tone threshold, but our
tests are designed to measure hearing abilities that are enhanced by the
listener having two ears."
Added senior engineering major Michael
Kessler, "Sound-localization is directly related to the users ability to
hear from both ears. A sound originating at the right ear will arrive at the
right ear some amount of time before arriving at the left ear. The difference
in time of arrival is known as interaural time delay. Designing a free-field
sound-localization test based on the principles of ITD and head shadow provides
a way to quantify the difference in hearing between a monaural and a binaural
listener."
One of the tests requires patients to
identify which of eight speakers a sound is coming from. The sound is
controlled by the software, which randomly selects a speaker to play the sound.
Another test requires patients to figure out what a voice is saying while noise
is coming from a different speaker.
A tricky part of designing the system
is calibrating it so people with unilateral hearing loss fail most of the time
and people with two good ears succeed most of the time. That's where Ganev, who
is deaf in her right ear, has focused. But finding people to test has been
difficult and some tests have been run placing an earplug in an ear of people
with normal hearing.
"It was interesting that we (people
with normal hearing but with an earplug ) were worse than people who have lived
their whole life hearing out of only one ear," Gray said. "So Sofie
has an interesting hypothesis about how we might learn to do that."
There have been hurdles to overcome in
designing the system too. "What Jonathan (Smith) and I have been working
on this semester and part of last semester is the user aspect, making sure the
user knows where to connect certain pieces, working on the instructions, making
it so you don't have to have a high level of familiarity with the technology to
set it up," said Brian Allen. "In our original design, they had 30
things to connect and now we're down to 10 or 11."
Allen also has been busy creating parts
for the system and its packaging with a 3-D design program and a 3-D printer. Lancaster
said the design may be further refined based on testing that will be
videotaped. The junior engineering students,
Brittany Harwell and Tony Battu, will continue to work with Nagel and Gray to
refine the design as well as scale up testing with post surgery patients during
the next academic year.
In addition to the symposium at JMU,
the team will be presenting the project April 26 at the 2013 IEEE Systems and
Information Engineering Design Symposium at the University of Virginia. The
event will provide an opportunity for the group to present their work to other
engineers and will result in the publication of a paper.
Gray said he is considering
collaborating with the University of North Carolina, where the hearing test
could be useful for testing aural atresia patients who are receiving an
implantable device, which was designed by JMU Professor Jonathan Spindel,
rather than surgery. The test could help determine if one remedy is better than
the other, he said.
By Eric Gorton ('86, '09M) and James Hong ('14)
Published April 12, 2013
