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In the acoustical section describing the signal
to noise ratio, it is discussed that children hear differently than
adults. This really should not be a surprise, when considering the
neurological component of the hearing process. The human auditory
brain structure is not fully mature until age 15; thus, a child
does not bring a complete neurological system to a listening situation.
(Bhatnagar, 2002, Boothroyd, 1997; Chermak & Musiek, 1997.)
What this means is that children are slower at processing the sounds
they hear, and cannot always “fill in the blanks” for
missed, muffled, or inferred auditory information. They simply do
not have the “historical” data or life experience that
enables adults to fill in the gaps and help them make sense of what
they hear. Such a process is referred to as auditory or cognitive
closure, and adults have had years, even decades to develop it.
The following examples demonstrate the difference between the way
adults and children “hear” information:
Example 1: Actual 1st graders were
asked to complete the following colloquial phrases that are well
known by adults. Here are a few answers from the study:
- “Better to be safe than……..punch a fifth grader.”
- “Don’t bite the hand that……..looks dirty.”
- “You can’t teach an old dog, new……..math.”
- “A penny saved is……..not much.”
- “Children should be seen and not……spanked
or grounded”
- “If at first you don’t succeed…….get
new batteries.”
This illustrates how adult brains automatically
fill in the end of the phrase based on our experiences. The humor
lies in the answers given by first graders who base their answers
on their own life experiences. Children receive very different messages
and/or interpretations of what they “hear” than do adults.
Example 2: A visual demonstration
of how jumbled sounds can be easily corrected by adults and understood;
not so by children:
I cdnuolt blveiee taht I cluod aulaclty
uesdnatnrd waht I was rdanieg The phaonmneal pweor of the hmuan
mnid Aoccdrnig to rscheearch taem at Cmabrigde Uinervtisy, it deosn't
mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt
tihng is taht the frist and lsat ltteer be in the rghit pclae. The
rset can be a taotl mses and you can sitll raed it wouthit a porbelm.
Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef,
but the wrod as a wlohe. Such a cdonition is arppoiately cllaed
Typoglycemia.
Amzanig eh? Yaeh and yuo awlyas thought
slpeling was ipmorantt.
Imagine a child trying to make sense of this
letter. A five year old could not do it. A seven year old may get
a few smaller words, but not enough to understand the passage. A
ten year may be able to decipher the entire passage, but it would
take significantly longer and require more energy to do so, than
an adult. A fifteen year old should be able to do this in an acceptable
amount of time.
If you find this concept difficult to understand,
just ask yourself, do you know any child under the age of ten who
understands the art of sarcasm? Chances are you do not because children
that young haven’t been exposed to language used in that manner,
at least not often enough to store-up a collection of historical
uses and meanings. At that point in their life children are still
very literal.
Children’s language skills and stored information
simply are not as detailed or complete as an adults, which prevents
them from “figuring out” what was said when the acoustical
environment precludes the information being heard clearly. This
is why children must have a quieter environment and a louder signal
(Anderson, 2001) than an adult would require for intelligible comprehension;
actually nine decibels louder than an adult.
To illustrate the difference in ability to listen accurately
to speech, a study examined the loudness or intensity
required for different ages to achieve 100% listening
accuracy. This studyi varied decibel levels
of speech materials and found that adult listeners
required a signal of only 11 dB sound pressure
level (SPL) to achieve essentially 100%
correct performance using the NU-CHIPSii testing
procedure. In contrast, children at age 10 required
18 dBSPL, at age 5 required 25 dBSPL and
at age 3, children required 38 dBSPL. The speech
materials were presented in a quiet setting.
It seems obvious that if a child cannot hear something
clearly, he or she might miss out on information and suffer academically,
but what about the personal and social implications of the failure
to hear? A study at Cornell University in 2001 and one at London
University in 2005, found that if students can’t focus on
the spoken word of the teacher, they not only lose the desire but
also the physical ability to learn. The process of hearing requires
a considerable amount of physical and mental energy; particularly
for children whose immature auditory capabilities slow down the
process that occurs automatically for adults. As an adult, try to
think what it is like at a wedding reception when the music is very
loud, and you have difficulty conversing with the other guests.
It is physically draining to have to concentrate that hard to understand
what someone else is saying. You may even choose to end the conversation
and walk away. Now imagine if those guests spoke a foreign language
and you had limited foreign language skills. You most likely would
experience extreme fatigue and frustration. These scenarios aren’t
very different than what children experience when they have difficulty
hearing, either from the environmental conditions, a physical impairment,
or a combination of both.
Hearing requires a lot of energy and stamina. If
that energy can be conserved by improving acoustic accessibility,
it can be channeled toward higher academic purposes. Unfortunately,
we don’t realize how much energy hearing requires, especially
in an acoustically deprived environment. Unlike our eyes that show
visible signs of strain when we have insufficient lighting, our
ears are not as obvious when being deprived of sound. Yet the harmful
results are the same. When someone reads excessively in a dark environment,
their eyes become red and sore. They begin to blink, miss reading
words, and have to needlessly read over what they have already read.
When our hearing is strained, we also become fatigued. We tune out
and unconsciously miss-hear information sometimes never even realizing
it, and information needs to be needlessly repeated. This is more
likely to happen to children than adults, because of those immature
auditory capabilities. Poor classroom acoustics exacerbate the problem,
often resulting in children becoming disengaged and losing focus.
An immature auditory capability in an acoustically
deficient environment puts all children at risk
for losing the attention and desire to learn.
A significant number of investigators have
demonstrated that inappropriate levels of classroom
noise and reverberation can deleteriously affect
not only speech-recognition ability, but
also psychoeducational and psychosocial development
(e.g. Bess &
Tharpe, 1986; Blair, Peterson, & Viehweb, 1985; Crandell &
Bess, 1986; Crandell & Karasik-Rush 1990, 1991; Davis, Elfenein,
Schum, & Bentler 1986; Finitzo-Hieber, 1988; finitzo-Hieber
& Tillman, 1978; Leavitt & Flexer, 1991; Ross, 1978; Ross
& Giolas, 1971). iii This may help to explain the growing
epidemic of ADD and ADHD, an apparent phenomenon
unique to America, and it
legitimately questions their diagnosis. The United
Nations released a report in February of 1996 expressing
concern over the discovery
that 10 percent to 12 percent of all male school
children in the United States take the drug methylphenidate
(Ritalin), a rate far
surpassing that of any other country in the world.
This growing epidemic explains why the U.S. consumes
90% of 8.5 tons
of Ritalin produced world-wide each year, iv and why use
of this drug, which is a stimulant related to
amphetamine, has increased by 700%
since 1990. v
The notion of ADD being linked to a hearing problem
is not unheard of. Kay Ness, a neurodevelopmentalist was quoted
saying, “Many children that are labeled ADD or ADHD have very
distorted hearing. I suspect that up to 70% of the children on Ritalin
are on it for this specific reason.” vi This opinion was reached
after studying the number of hearing problems and infections encountered
by those children taking Ritalin. Do not make the mistake of trivializing
hearing problems triggered by the environment as compared to those
innately physical. The effects are the same. The inability
to hear (clearly) causes ALL children, even those with the best
intentions to pay attention, to disengage themselves from auditory
learning. |