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As printed in Hearing Health, volume 19:2,
Summer 2003
By Mike Nixon
An ever-rising number of households with two working
parents or a single custodial parent who is employed
has created an increasing need for preschool childcare
outside the home. While extended family members care
for the majority of preschoolers of working parents,
about five million of our smallest children attend commercial
or institutional daycare centers.
The types of programs that are available for them and
the facilities where they are provided vary widely.
There are many factors to consider when choosing among
daycares in your area. Certainly, appropriate certification
and education for the program workers and a safe and
secure environment top the list. An often overlooked
variable ranks nearly as high: the noise levels that
exist within the setting.
As is well-established, exposure to excessive noise
over prolonged periods is potentially harmful to hearing.
That of course is one concern as our preschool children
are frequently in loud daycare settings for as long
as eight to 10 hours of the day. Another is the detrimental
effect on learning, language and socialization caused
by the inability of young children to listen successfully
in noisy environments. Effective acoustical environments
can improve speech intelligibility which is critical
for speech development.
Very young children need low background noise and very
low reverberation time (RT) levels to perceive speech
at optimum levels. This is particularly critical where
there are many young children in the room. High background
noise levels and sound reflective hard surfaces can
cause a noise buildup as the children talk more loudly
and compete with one another in order to hear and be
heard. At times the resulting noise levels can best
be characterized as a clamorous din.
The additional agitation and stress of the elevated
noise levels can heighten the effects of the child's
inability to perceive speech, further compromising attention,
concentration and increasing negative behavior.
Caregivers too can be at risk by having to raise their
voices to a point where they experience vocal fatigue.
Furthermore, daycare providers and teachers exposed
to a constant barrage of loud sound can become tired
and irritable and experience heightened stress.
Daycare centers and preschool facilities range from
converted commercial establishments to church facilities
and community centers. Some school districts incorporate
preschools in newer school buildings. Regardless of
the facility, it is likely that the vast majority of
these settings has not been designed or modified to
effectively reflect the critical needs of very young
preschool children and even more especially children
with auditory related deficits.
While acoustical standards for school facilities have
been developed and adopted by the American National
Standards Institute (ANSI), they address the acoustical
and noise issues for elementary schools and above. Criteria
for daycare centers or preschool facilities are not
yet included. Nevertheless, we can draw on the ANSI
standards for some measure of guidance on improving
the listening environment for our children in daycare
and preschool.
The design and layout of the daycare or preschool facility
is especially important if it is to be user-friendly.
If the facility is an open plan arrangement, there is
an expectation that the noise levels will be much higher
due to the increased occupancy. Totally contained smaller
spaces on the other hand are much more likely to be
quieter.
The ANSI standards for classroom acoustics recommend
that the reverberation time in a typical classroom of
10,000 cubic feet or less should not exceed 0.6 seconds.
Excessive reverberation can lead to a smearing of the
speech signal due to late arriving reflected sound as
heard by the listener. For preschoolers as well as young
children with hearing deficits, there has been some
suggestion that the reverberation time should be lower,
perhaps in the range of 0.4-0.5 seconds. The recommended
background noise levels of 35 decibels in unoccupied
classrooms would be equally applicable for preschool
facilities.
When selecting a daycare center or preschool facility,
armed with the knowledge that the acoustical environment
will have an impact on both children and their caregivers,
parents can evaluate the facilities by observing the
following:
- Is the daycare facility an open concept with no
subdivision into small self-contained rooms? This
space could be very noisy.
- If the space is an open plan, is it one large area
or is it divided into smaller spaces set off by high
partitions or screens? Noise may still be a problem.
- How many children are in attendance? The more children,
the noisier the space, in most cases.
- What are the architectural conditions of the space(s)?
Is the ceiling a high ceiling or is it an acoustical
ceiling? Are the wall and floor surfaces hard and
acoustically reflective? The higher the ceiling, the
higher the RT. If there is no acoustical ceiling,
the noise could be intolerable. Sometimes with a very
high acoustical ceiling, the RT can still be unacceptable
as it can if the walls and floors are hard surfaced.
- A hand clap in the facility can often determine
how reverberative the space is. If the hand clap sounds
hollow, the RT in the space might be higher than it
should be. The sound of a hand clap at the acceptable
0.4 - 0.5 second RT level is about the same as in
an average living room with carpet and upholstered
furniture.
- Can you hear background noises from the heating/ventilation
system or from exterior sources when the space is
empty? If you can hear these noises easily, the space
may not comply with ANSI acoustical standards. The
recommended 35 decibel background noise level is once
again about the same level as an unoccupied living
room.
- If the facility has a kitchen area, is it self-contained
or is it part of the larger open space? Kitchen areas
that have dishwashers can contribute noise that is
unacceptable as can dish and cutlery noise while storing
them after meals or snacks.
Attending daycare or preschool can be an important
opportunity for a child to gain social skills and interact
with adults and other children. The architecture of
the facility must be friendly, comfortable and support
good speech intelligibility, learning and discipline.
These characteristics can help insure that the daycare
or preschool setting will have a positive impact on
the child during a critically important formative time
of life.
Mike Nixon, president of EA Acoustical
Engineering Inc. and a long time advocate for acoustical
accessibility, was a member of the ANSI working group
responsible for the development of the ANSI Classroom
Acoustical Standards. Readers can contact him at mtnixon@aol.com. |
