1. Remote-Microphone Technology Fitting Procedures for Normal Hearing Children with Auditory Disorders
Arun Joshi, BS, Suzanne Wright, BA, Christine Anderson, BS, & Erin Schafer, PhD
The University of North Texas
.
METHODS
CONCLUSIONS
American Academy of Audiology. (2008) Clinical Practice Guidelines for
Remote Microphone Hearing Assistance Technologies for Children
and Youth from Birth to 21 Years. Reston, VA: Strategic Documents
Committee, Hearing Assistance Technology Task Force.
Schafer EC, Bryant D, Sanders K, et al. (2014a). Fitting and verification
of frequency modulation (FM) systems on children with normal
hearing. J Am Acad Audiol, In press
Schafer, E. C., Traber, J., Layden, P., Amin, A., et al. (2014b). Use of
wireless technology for children with auditory processing disorders,
attention-deficit hyperactivity disorder, and language disorders.
Seminars in Hearing, 35(3), 193-205
REFERENCES
There are several populations of children who have
normal hearing but exhibit auditory listening difficulties in
the classroom. Moreover, there is strong subjective,
behavioral, and objective research evidence to support
the presence of auditory processing dysfunction in
normal hearing children with auditory disorders, including
those diagnosed with Autism Spectrum Disorder (ASD)
(Schafer et al., 2014b). Recent publications support the
use of wireless, remote-microphone (RM) technology for
improving speech-recognition performance in noise and
classroom-listening abilities in children diagnosed with
auditory processing disorder (APD), attention-deficit
hyperactivity disorder (ADHD), and ASD. As a result, an
evidence-based remote-microphone (RM) technology
fitting procedure is warranted. An overview of two
previous studies will be used to outline fitting procedures
for normal hearing children with auditory disorders. The
primary goal of the first study (Schafer et al., 2014a) was
to determine the validity of the AAA real-ear approach
(2008) to fitting FM systems on children with normal
hearing. The second study (Schafer et al., 2014b)
replicated the fitting procedures from the first study on
children who were diagnosed with the aforementioned
disorders.
Participants
Study 1: 26 children, 5 to 12 years, with typical
speech/language development and normal hearing
thresholds of less than 25 dB HL from 250 to 6000 Hz.
Study 2: 12 children, 6 to 11 years, with normal hearing
thresholds of less than 20 dB HL from 250 to 6000 Hz.
Equipment
Participants in both studies were fit with bilateral Phonak
iSense Micro FM receivers with Standard xReceivers and
small domes. The receivers were synched to an inspiro
transmitter. Real-ear measures were conducted using an
Audioscan Verifit.
METHODSINTRODUCTION
Fitting Procedures
1. Meet DSL targets at 1000, 2000, 3000, & 4000 Hz
FM mic in the test box; real-ear mic in child’s ear; Verifit: select
‘FM’; ‘On-ear’; Speech-std[1]; FM volume adjusted, if necessary
2. Do not exceed estimated UCL
Same settings, but MPO selected as the stimulus; Compared MPO
to the estimated UCL
3-4. Examine difference between REOR & REUR
Transmitter turned off; Verifit: ‘Open’ instrument; Speech-std[1] at
65 dB SPL.
Speech Recognition in Noise
In both studies, fixed-intensity BKB-SIN sentences were presented
at 0 degrees azimuth (60 dBA) with multitalker babble from 3
spatially-separated loudspeakers (65 dBA). Participants completed
4 conditions: (1) no FM system, (2) FM receiver on the right ear, (3)
FM receiver on the left ear, and (4) bilateral FM receivers.
Loudness Ratings
In both studies, participants listened to BKB-SIN stimuli (+5 SNR)
and were asked to rate the loudness of the same four conditions on
a rating scale to confirm similar loudness ratings.
Study 2 Questionnaires & Listening Comprehension
Before and after a RM technology trial period, parents and
participants completed the Children’s Home Inventory for Listening
Difficulty (C.H.I.L.D.). Some participants and teachers also
completed the Listening Inventory for Education-Revised (L.I.F.E.-
R) Children’s Auditory Performance Scale (C.H.A.P.S.). The
children’s listening comprehension in noise was determined with an
investigator-recorded version of the Listening Comprehension Test
2 in the presence of continuous four-classroom noise.
0
10
20
30
40
50
60
70
80
90
100
110
Left FM Right FM Bilateral
FM
No FM
PercentCorrectSpeech
Recognition
Listening Condition
5-8 yrs
9-12 yrs
The proposed fitting procedures met DSL targets, did not
exceed UCLs, and produced minimal occlusion. The fitting
resulted in “comfortable” or “comfortable but slightly loud”
loudness ratings for all condition. All behavioral measures
and questionnaires yielded significantly better results with the
RM technology.
30
40
50
60
70
80
90
100
110
1000 2000 3000 4000
dBSPL
Frequency (Hz)
Target
Output
No significant effect of output
type
RESULTS
Figure 1. Fitting Goal #1: Meet DSL targets
Identical results for Study 1 & 2
RESULTS
30
40
50
60
70
80
90
100
110
250 500 1000 2000 3000 4000 6000
dBSPL
Frequency (Hz)
UCL
Output
Figure 2. Fitting Goal #2: Do not exceed UCL
Identical results for Study 1 & 2
MPO significantly lower
than estimated UCL
0
10
20
30
40
50
60
70
1000 2000 3000 4000
dBSPL
Frequency (Hz)
iSense
Unaided
Figure 3. Fitting Goal #3: Avoid occlusion effect
Only done in Study 1
Significant difference of 3 dB, not
clinically relevant
Figure 4. Speech recognition (Identical results for Study 1 & 2)
No significant differences;
but we only do bilateral
FM/DM!
-2
3
8
13
18
ListeningTestScore
Subtest
Unaided
FM
Significantly higher comprehension with
FM
Figure 5. Listening Comprehension
Only done in Study 2
0
5
10
15
20
25
30
35
Quiet Noise Distance Social Media
ParentC.H.I.L.D.Rating
Listening Condition
Baseline
With FM
Figure 6. Parent C.H.I.L.D. Ratings
Only done in Study 2
Significantly higher ratings with FM
Funding for participant payment and equipment was provided by Phonak. We would also like to thank the participants in our study!
ACKNOWLEDGEMENTS