Background Noise:
Classroom, Clinic and
(Research) Lab
Jill Raney, Ph.D.
April 11, 2014
University of Connecticut
Overview
Presence of background noise in
classrooms
Standards for Classroom Acoustics
Measuring impact of background
noise
Interventions
What is current research telling us.
Distance (Speaker to the listener )
–Double the distance, decrease signal by 6
dBReverberation –Persistence of the reflected sounds after
the original sound is produced. Longer
time greater the difficulty.
Noise –Greater the background noise the
poorer the Signal/Noise ratio (S/N)
Classroom Acoustic
Standards2002 - American National Standards Institute (ANSI)
created the, Acoustical Performance Criteria, Design
Requirements and Guidelines for Schools standard (ANSI
S12.60-2002). Standard developed in a effort to create a
classroom environment that optimizes speech
understanding.
2004 - American Speech-Language-Hearing Association's
(ASHA) endorsed the ANSI standard and recommended
the following criteria for classroom acoustics:
• Unoccupied classroom levels must not exceed 35
dBA
• The signal-to-noise ratio (S/N) should be at least
+15 dB at the child's ears.
• Unoccupied classroom reverberation not longer
than 0.6 seconds in smaller classrooms or 0.7
seconds in larger rooms
Clinic
Auditory Skill Development: Speech understanding in background noise
Children are not “little adults”.
Elliot, L. (1979). Performance of
children aged 9 to 17 years on a test
of speech intelligibility in noise using
sentence material with controlled
word predictability. Journal of the
Acoustical Society of America, 66,
651-653.
Which children have difficulty
understanding speech in
background noise? Most!
• Normal hearing
• Hearing loss
• Sensorineural
• Conductive
• Unilateral
• Central Auditory Processing Disorder (CAPD)
• Aspergers
Some of the Available SIN
Tests• Words-in-Noise Test (WIN) (Wilson, 2003;
Wilson & McArdle, 2007)
• Quick Speech-in-Noise Test (QuickSIN)
(Killion et al., 2004)
• Hearing in Noise Test (HINT) (Nilsson et
al., 1994)
• BKB-Speech in Noise Test (BKB-SIN)
(Etymotic Research, 2005)
• Listening in Spatialized Noise - Sentences
Test (LiSN-S) (NAL – National Acoustic
Laboratories)
Speech-In-Noise (SIN) Testing:
Quantify the amount of
difficulty.
Stimuli: Digits
Words
Sentences
Noise: Speech-spectrum
Cafeteria
Multi-talker babble
Presentation: Modified Live-Voice (MLV)
Recorded
What can we do?
Improve the S/N
• Decrease the level of the noise (N)
• Increase the level of the signal (S)
FM - Phonak
iSense
Inspiro
Practice
Auditory Training Programs
LACE - Listening And Communication
Enhancement (Neurotone)
(LiSN-S)- Listening in Spatialized Noise
– Sentences Test (National Acoustics
Lab)
Lab - Why is noise detrimental to
speech understanding?
Dr. Nina Kraus’ Work
Audiology Online – From20Q with Gus Mueller (7/13)
Marion Downs Lecture in
Pediatric Audiology (AAA, 2014)
“Biological Assessment in
Audiology: Spotlight on Auditory
Processing and Hearing in
Noise.”
Presented by Dr. Nina Kraus
Does FM Use and Training
Work?
Summary
Presence of background noise in
classrooms
Standards for Classroom Acoustics
Measuring impact of background
noise
Interventions
What is current research telling us.
As Helen Keller said,
“Blindness separates us
from things but deafness
separates us from
people."
Thank you…