[Federal Register Volume 63, Number 104 (Monday, June 1, 1998)]
[Proposed Rules]
[Pages 29679-29686]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14442]
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ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD
36 CFR Chapter XI
[Docket No. 98-4]
Petition for Rulemaking; Request for Information on Acoustics
AGENCY: Architectural and Transportation Barriers Compliance Board.
ACTION: Request for information.
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SUMMARY: The Architectural and Transportation Barriers Compliance Board
has received a petition for rulemaking from a parent of a child with a
hearing loss requesting that the ADA Accessibility Guidelines be
amended to include new provisions for acoustical accessibility in
schools for children who are hard of hearing. Several acoustics
professionals, parents of children with hearing impairments,
individuals who are hard of hearing, and a consortium of organizations
representing them have also urged the Board to consider research and
rulemaking on the acoustical performance of buildings and facilities,
in particular school classrooms and related student facilities. The
Board seeks comment on the issues outlined in this request for
information. After evaluating responses to this request for
information, the Board will determine a course of action. Alternatives
under consideration include research, rulemaking, and technical
assistance on acoustical issues.
DATES: Comments should be received by July 31, 1998. Late comments will
be considered to the extent practicable.
ADDRESSES: Comments should be sent to the Office of Technical and
Information Services, Architectural and Transportation Barriers
Compliance Board, 1331 F Street NW., suite 1000, Washington, DC 20004-
1111. E-mail comments should be sent to acoustic@access-board.gov.
Comments sent by e-mail will be considered only if they include the
full name and address of the sender in the text. The petition and
comments are available for inspection at the above address from 9:00
a.m. to 5:00 p.m. on regular business days.
FOR FURTHER INFORMATION CONTACT: Lois Thibault, Office of Technical and
Information Services, Architectural and Transportation Barriers
Compliance Board, 1331 F Street NW., suite 1000, Washington, DC 20004-
1111. Telephone number (202) 272-5434 extension 32 (voice); (202) 272-
5449 (TTY). These are not toll-free numbers. Electronic mail address:
thibault@access-board.gov.
SUPPLEMENTARY INFORMATION:
Availability of Copies and Electronic Access
Single copies of this publication may be obtained at no cost by
calling the Access Board's automated publications order line (202) 272-
5434, by pressing 1 on the telephone keypad, then 1 again, and
requesting publication C-11. Persons using a TTY should call (202) 272-
5449. Please record a name, address, telephone number and request
publication C-11. This document is available in alternate formats upon
request. Persons who want a copy in an alternate format should specify
the type of format (cassette tape, Braille, large print, or computer
disk). The petition and this request for information are also posted on
the Board's Internet site at http://www.access-board.gov/rules/
acoustic.htm.
Background
The Architectural and Transportation Barriers Compliance Board
1 (Access Board) is responsible for developing accessibility
guidelines under the Americans with Disabilities Act of 1990 (ADA) to
ensure that new construction and alterations of facilities covered by
the law are readily accessible to and usable by individuals with
disabilities. The Access Board initially issued the Americans with
Disabilities Act Accessibility Guidelines (ADAAG) in 1991. The
guidelines contain scoping provisions and technical specifications for
designing elements and spaces that typically comprise a building and
its site so that individuals with disabilities will have ready access
to and use of a facility.
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\1\ The Access Board is an independent Federal agency
established by section 502 of the Rehabilitation Act (29 U.S.C. 792)
whose primary mission is to promote accessibility for individuals
with disabilities. The Access Board consists of 25 members. Thirteen
are appointed by the President from among the public, a majority of
who are required to be individuals with disabilities. The other
twelve are heads of the following Federal agencies or their
designees whose positions are Executive Level IV or above: The
departments of Health and Human Services, Education, Transportation,
Housing and Urban Development, Labor, Interior, Defense, Justice,
Veterans Affairs, and Commerce; General Services Administration; and
United States Postal Service.
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Although ADAAG contains a number of provisions for access to
communications, including requirements for text telephones, assistive
listening systems, and visible alarms, it does not include provisions
for the acoustical design or performance of spaces within buildings and
facilities.
[[Page 29680]]
The Department of Justice (DOJ) regulations implementing titles II and
III of the ADA contain additional requirements for communications with
individuals with disabilities and for auxiliary aids and devices to aid
in communication.2
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\2\ Under the ADA, the Departments of Justice and Transportation
are responsible for issuing regulations to implement titles II and
III of the Act. The regulations must include accessibility standards
for newly constructed and altered facilities. The standards must be
consistent with the accessibility guidelines issued by the Access
Board. The Department of Justice and the Department of
Transportation regulations currently include ADAAG 1-10.
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On April 6, 1997, the Access Board received a petition for
rulemaking from a parent of a child with a severe to profound hearing
loss requesting that the Board address ``architectural acoustics in
schools'' and develop ``new rules'' for children who are hard-of-
hearing. The petition argues that children who have hearing and other
disabilities, including learning, auditory processing, speech and
language, and developmental disabilities, face numerous communications
barriers in schools because of poor acoustics and that these barriers
may prevent them from receiving a meaningful education. The petition
requests that the Board develop ``acoustical guidelines * * * [to]
ensure adequately low noise and reverberation so that the speech-to-
noise ratio and speech-to-reverberation ratio allow satisfactory
communication and learning.''
A consortium of organizations representing persons with
disabilities (Alexander Graham Bell Association for the Deaf, Inc., the
American Speech-Language-Hearing Association (ASHA), Auditory-Verbal
International, Inc., the National Center for Law and Deafness, the
National Cued Speech Association, and Self Help for Hard of Hearing
People (SHHH)) submitted comments to the Board in previous rulemakings
asserting that a poor acoustical environment is as significant a
barrier to individuals with hearing, speech, and language impairments
as stairs are to persons who use wheelchairs.
The consortium's comments included a position paper on acoustics in
educational settings developed by ASHA in 1994. The paper cited data on
the increasing prevalence of hearing loss, particularly among children
and young adults, and reported on research that identified children
with mild hearing losses as more at risk for general psychosocial
dysfunction and lags in academic progress than were children with
normal hearing. Other cited studies showed the relationship between
poor room acoustics and low speech comprehension in children with
hearing, learning, and developmental disabilities. Reverberant
classrooms with high ambient noise levels were identified as
significant contributors to communications difficulties. The position
paper included a number of recommendations for the acoustical
performance of classrooms to improve conditions for listening, hearing,
and understanding speech.
Other commenters to ADAAG rulemakings noted that the acoustics of
many restaurants adversely affected the ability of individuals who are
hard of hearing to communicate with companions and with service staff.
In response, the Access Board contracted with Batelle, a research
organization in Columbus, OH, to study improved speech communication
for persons with hearing impairments in dining areas. A literature
study, post-occupancy evaluations of several facilities, and
recommendations were developed by Batelle engineers and reviewed by an
eight-member advisory panel. The authors identified background noise
levels and reverberation as the acoustical characteristics most subject
to design and construction manipulation and most significant for
adequate speech communication. Several panel members suggested that
other facility types, particularly schools, could benefit from the
application of such acoustical requirements.
Hearing Loss and Other Disabilities
Government health statistics document that more Americans report a
hearing loss than any other disability, and the incidence of hearing
loss has increased significantly in the last 25 years. A recent
assessment by the Centers for Disease Control and Prevention (CDC)
found that 13% of a representative sample of children between the ages
of 6 and 19 had a high frequency hearing loss and 7% a low frequency
hearing loss of 16 dB or more, a level at which perceiving and
understanding words would be affected.
Increasing numbers of young children experience mild temporary and
recurring hearing loss caused by otitis media, an inflammation of the
middle ear that is the most frequent medical diagnosis for children.
Research also shows that children with learning, speech, and
developmental disabilities have a higher incidence of abnormal hearing
and of repeated instances of ear problems. ``Hearing Loss: The Journal
of Self Help for Hard of Hearing People'' reported in 1997 that one-
fourth to one-third of the students in typical kindergarten and first-
grade classrooms will not hear normally on a given day.
Speech Communication
Effective speech reception--understanding, not just hearing--is the
primary educational issue for people with auditory disabilities. A
Cornell University study published in the journal ``Environment and
Behavior'' indicates that excessive classroom noise impedes the
acquisition of language and cognitive skills by all children. The
acquisition of language is necessary for brain and intellectual
development. Research with children who are deaf has shown that the
mastery of a system of communication is essential to future learning
and that failure to acquire effective language skills by the age of six
cannot be fully remediated.
Language acquisition is dependent in large part upon exposure to an
organized system of communication, such as a signed, voiced, or tactile
language. For children who will use voice communication, the
intelligibility of the spoken language is a critical factor. Speech
intelligibility is a measure of the proportion of the spoken message
that gets through to the listener, and is affected by signal volume,
the distance between the speaker and listener, and the acoustic
characteristics of the room, including background noise levels and
reverberation time.
A large body of clinical and scientific research supports the
particular need for good acoustics in teaching environments. The
Acoustical Society of America (ASA) has established a Classroom
Acoustics Subcommittee of its Architectural Acoustics Committee that
has held four symposia on classroom acoustics issues. At an ASA
conference held in June 1997, researchers presented evidence that
excessive noise levels impair a young child's speech perception,
reading and spelling ability, behavior, attention, and overall academic
performance.
Because the ability to understand speech does not mature in
children before the age of 15, children are less effective listeners
generally than are adults. Additionally, children have less experience
in deriving meaning from context. A representative sample of children
without hearing loss or other audiological disability, even when tested
in above-average listening environments, could make out only 71% of a
teacher's words. Those in the worst environments ``got'' only 30% of
the message directed at them.
The listening abilities of children with hearing impairments,
particularly those with mild to moderate hearing loss, are even more
affected by poor acoustics than are those of children whose hearing
falls within normal
[[Page 29681]]
ranges. A 1997 study of children with minimal sensorineural hearing
loss showed lower scores for basic skills and communications testing
and a high rate--37%--of retention in grade. In addition, these
students functioned below normally hearing children in evaluations of
behavior, energy, stress, social support, and self-esteem. Other
studies have shown that children with learning and developmental
disabilities perform less effectively in noisy spaces.
In their chapter on ``Speech Perception in Specific Populations''
(from the book ``Sound-Field FM Amplification''), Drs. Carl Crandell,
Joseph Smaldino, and Carol Flexer have identified at-risk populations
as young students generally (less than 13-15 years of age); children
who have a history of otitis media, children for whom English is a
second language, and children with auditory disabilities, including
those with hearing loss, central auditory processing deficits, learning
disabilities, developmental delay, and attention, speech, and language
disorders.
Acoustical Performance of Rooms and Spaces
In analyzing how effectively an individual can hear and understand
in a given space, an acoustician or audiologist will consider three
criteria: Distance from the sound source (the `signal'), the level of
background sound (noise), and the effects of reverberation. By
controlling background noise levels and room reverberation time,
designers can provide good speech intelligibility, measured by the
signal-to-noise ratio. The signal-to-noise ratio is the relationship
between the loudness of the message and the background sound it must
overcome to be heard and understood. A significantly positive signal-
to-noise ratio is necessary for maximum performance where room sound
levels are high; children with hearing impairments require a higher
signal-to-noise ratio than do children with normal hearing.
Distance from the source has a significant effect on signal-to-
noise ratio, since the loudness of a direct sound falls off in
proportion to the distance between the speaker and listener. Children
with hearing impairments and other disabilities affecting listening
need to maintain a consistent and close relationship with the sound
source. Speech intelligibility can be enhanced by delivery and
performance styles, by the use of reflective surfaces at the speaking
location, and by amplification.
Background noise--whether from heating, ventilating, and air
conditioning (HVAC) systems, other noise generated within the space, or
outside noise--also interferes with effective listening because it
competes with the spoken message. High background noise values across
the frequencies of speech (500 to 2000 Hz) require louder speech
signals to overcome. Background noise (or ambient sound) design
criteria are typically expressed as a range between two noise criteria
(NC) curves, which plot sound levels across 8 standard frequencies.
Sound levels in existing spaces can be tested at these frequencies
using a sound meter. The NC rating for a room is typically between 5 to
10 points below the dBA reading. Design engineers can specify HVAC
equipment with low noise ratings and limit sound generated by system
operation in a variety of ways. Rooms and spaces can be protected from
unwanted exterior sound by mass, insulation, and isolation in wall and
slab construction and by minimizing (or sound protecting) openings.
Reverberation--reflected sound that persists within a room or
space--also masks the sound of the spoken message and increases
background sound levels. The longer the reverberation time, the greater
the effect. Reverberation is expressed in seconds (R60), measured as
the time it takes for sound to decay 60 dB after the source has stopped
producing it. Reverberation is a function of the physical properties of
the room and can be calculated if the volume, surface area, and surface
absorbencies of a space are known. Reverberation can be controlled by a
manipulation of the absorbency of surfaces within a space and the
proportions and volume of the space.
When reverberation time and background noise are controlled, speech
effort and sound levels decline, leading to a reduction in room noise.
It has been estimated that over 90% of those who have a hearing loss
have usable residual hearing and would benefit from an enhanced speech
environment. Where classrooms and child care centers do not provide
acceptable listening conditions, even amplification will not achieve
maximum effect in improving speech communication. Poor acoustics can
also compromise the effectiveness of personal hearing aids and devices
and limit the usefulness of auxiliary aids and services. Good acoustics
can enhance the usefulness of such aids and improve listener reception
of unamplified speech, as may occur in group interchange. Because most
mild hearing losses in children are not diagnosed, children with such
losses (15-25 dB), including those with temporary hearing loss due to
otitis media, will not generally be using amplification devices.
Many groups concerned with the acoustics of educational
environments recommended that new implementing regulations for the
Individuals with Disabilities Education Act (IDEA), currently being
developed by the U.S. Department of Education, require that services
for covered students be delivered in an acoustically appropriate
environment. Two cases have been reported to the Board in which IDEA or
Rehabilitation Act decisions directed that the room acoustics in
existing school classrooms be improved to accommodate children with
hearing loss. Requirements that students with disabilities be educated
in the least restrictive environment mean that every classroom is
likely to have a youngster with a diagnosed auditory disability in
attendance; additionally, during the course of a school year, many
children will be temporarily affected by mild and possibly recurring
hearing loss associated with otitis media and other illnesses.
Classroom Acoustics
Studies of classrooms around the country and test data submitted by
parents and acoustical consultants indicate that classrooms and day
care facilities are not being designed to provide adequate speech
intelligibility even for children without auditory impairments.
Research on seven child-care facilities in Canada documented noise
conditions in four centers that exceeded the 75 dB limit considered
safe for day-long exposure for adults by the World Health Organization.
Open plan centers had particularly excessive noise levels and were
reported to have more health problems among children and staff as well
as other disadvantages. Acoustical treatment that reduced reverberation
time in the noisiest setting from 1.6 seconds to .6 seconds resulted in
a 5 dB decrease in sound level and staff assessments of substantial
improvement in comfort. A 1994 survey of school facility conditions
conducted by the General Accounting Office (GAO) reported that poor
acoustics were ranked by administrators as the most significant problem
affecting the learning environment. Twenty-eight percent of responding
schools identified acoustics for noise control as being unsatisfactory
or very unsatisfactory. Eleven million children were estimated to be
affected. Of these, CDC estimates suggest, more than a million and a
half children may have a temporary or permanent hearing loss.
[[Page 29682]]
Acoustical Design Standards and Guidelines
Reverberation and background noise limits are common elements in
existing acoustical standards, recommendations, and good-practice
guidelines for classroom design and construction. Audiometry rooms and
educational classrooms designed specifically for persons with auditory
impairments have short reverberation times and very low background
noise levels. Similar requirements are applied to rooms such as
broadcast and recording studios, including teleconferencing facilities,
where speech communication is the primary function, and in sound
testing facilities such as anechoic chambers. Low background noise and
short reverberation times contribute to positive sound-to-noise ratios,
maximal sound transmission indices, and high speech intelligibility
values.
Achievements in the design of concert hall acoustics and
specialized environments for materials testing and measurement
demonstrate that good hearing environments can be accomplished with
current design, modeling, construction, and testing procedures. It
appears that a consensus on the general scope and content of acoustical
performance criteria for classrooms is developing among audiologists,
acousticians, and consumers and that existing acoustical guidelines for
educational and other facilities may be adaptable for incorporation
into ADAAG.
While some factors--for instance, a rise in exterior noise levels
due to a change in nearby noise sources--are beyond the control of the
design professional, `bad' acoustics are largely architectural
problems, solvable by architectural means. Architects and other design
professionals routinely practice simple acoustical design procedures in
specifying floor, wall, and ceiling finishes. Acousticians are
regularly retained for the more demanding design and engineering of
music and performance facilities. Several software programs are
available to model the acoustical performance of spaces that have been
designed but not built. Criteria for the acoustical design of spaces
are widely available in textbooks and technical publications.
Acoustical testing protocols are developed and maintained by
several private sector organizations. The American Society of Heating,
Refrigeration, and Air Conditioning Engineers (ASHRAE) issues standards
that include the acoustical performance of equipment installed in
buildings and facilities. The American National Standards Institute
(ANSI), in conjunction with the ASA, has established several protocols
for the measurement of room sound levels, including ANSI S12.2 Criteria
for Room Noise Measurement. ANSI has recently established a committee
to develop a classroom acoustics standard. Foreign and international
standards also exist. Model codes contain both standards and
requirements for sound-rated construction components in multi-family
housing and other occupancy types. The developers and operators of
hotel, medical, and housing facilities typically establish similar
acoustical standards for sound transmission through floors, walls,
structure, and HVAC systems.
``Architectural Acoustics'', by M. David Egan (McGraw-Hill, Inc.,
1988), a standard reference work for design professionals, recommends a
background noise level of less than 20 dB (NC-20) for critical music
performance (including broadcast and recording studios) and
audiological spaces; a range of NC-20 to NC-30 for less demanding,
speech-focused halls and rooms, and NC-30 to NC-35 for classrooms.
Recommended reverberation limits range between .6 and .8 seconds. The
author notes, however, that NC curves to provide satisfactory listening
environments for persons with hearing impairments need to be lower by 5
(resulting in a recommendation of NC-25 to NC-30 for classrooms serving
adults with hearing loss). Egan recommends that reverberation time in
such rooms should not exceed .5 seconds.
The ASA recommends an average reverberation time in classrooms
between .6 seconds minimum and .8 seconds maximum; ambient room noise,
when measured without occupants, between 30 dBA minimum and 35 dBA
maximum; room criteria (RC) curve--used to measure HVAC and equipment-
generated noise--should not exceed RC-25, and the signal-to-noise ratio
should be able to achieve +15 dB. The ASA has recently established a
multi-committee initiative to work on the development of guidelines for
acoustics. A workshop seminar was held in Los Angeles in December 1997
to begin the process of developing consensus recommendations.
The ASHA recommends that noise levels in unoccupied classrooms not
exceed 30 dBA (or a NC-20 curve) and that reverberation time not exceed
.4 seconds across speech frequencies. Signal-to-noise ratios (measured
at the student's ear) should exceed +15 dB.
Dr. Crandell et al. recommend that elementary and secondary school
classrooms for `at-risk' students should have unoccupied ambient noise
levels that do not exceed NC-25 or a sound pressure level of 35 dBA and
a reverberation time that does not exceed .4 seconds in the speech
frequency range.
Portugal's classroom noise standards, adopted in 1988, limit
reverberation time in general classrooms to .6-.8 seconds and in
special classrooms to .6 seconds; equipment background noise may not
exceed 35 dBA. Wall construction between classrooms must have a sound
transmission class (STC) rating of at least 50 dB. The Swedish Board of
Housing, Building and Planning has adopted Building Regulations BBR 94,
with amendments, that include detailed guidelines for protection
against noise for several building types, including schools, by means
of specified areas of sound absorbent surfaces within classrooms,
acoustical isolation between classrooms, and limits on background noise
from building systems and equipment.
The State of Washington Department of Health rules, WAC 248-64-320
Sound Control, include a limit (NC-35) on background noise in
classrooms. The Los Angeles County Unified School District--the largest
in the world in numbers of students enrolled--has recently adopted a
similar standard for the noise output of classroom HVAC equipment. ANSI
S12.2-1995 suggests an NC range of 25-30 for classrooms and an RC in
the same range. A tabular comparison of values for acoustical criteria
in classrooms is presented in Table 1.
Other bases for prescribing and testing acoustical characteristics,
including values for speech-to-noise ratio and the speech transmission
index (STI), may be applied to diagnose existing acoustical conditions
in classrooms, but do not appear useful in a new construction standard.
The STI takes into account the effects of noise and reverberation and
can be adjusted to obtain values for listeners with hearing
impairments. Both rely on in-use measurements.
Cost
High-performing acoustical environments are achieved at some
premium in construction cost. Knowledgeable design, construction, and
materials specification, an investment in high-quality HVAC equipment,
and careful installation and workmanship are required to ensure that
design values are reflected in performance. Special consideration of
room configuration, proportion, and location may also be necessary.
Furthermore, the measures necessary to
[[Page 29683]]
control sound in classrooms may raise other issues affecting cost. For
instance, carpeting is recommended to add absorbency for reverberation
control and to minimize the self-noise of student movement. However,
carpeting may require a change in maintenance procedures. Controlling
ambient noise in many urban schools may require that windows be kept
closed even in pleasant weather, when HVAC systems might operate at
lesser capacities. Students with moderate to severe hearing impairments
may also require the use of amplification systems to increase speech
intelligibility to effective values.
ADAAG Criteria
To be useful, acoustical recommendations and standards should
employ design techniques, data, and sound measurement protocols
available and familiar to architecture, engineering, and construction
practitioners and applicable during design phases. Like a building
code, ADAAG is intended for use in new construction and alterations of
buildings and facilities. It contains provisions for construction
elements, items, and finishes that are fixed to the building structure.
Furniture and equipment, including portable communications devices, are
covered by the DOJ regulation, not ADAAG.
The Board recognizes that amplification technologies may be
required for effective communications in some rooms and spaces and for
some individuals. Such solutions, including those that use portable
assistive listening systems and sound field technology, are beyond the
scope of the building and facility provisions in ADAAG. However, such
technologies cannot be fully effective in noisy environments;
amplification in highly reverberant environments will exacerbate
listening and hearing problems. Furthermore, the effectiveness of
personal devices, particularly hearing aids, is also compromised in
noisy environments. And, because the learning environment includes
interaction with peers and other individuals in classrooms and other
settings, instructor amplification only may not fully remove barriers
to hearing, listening, and learning where acoustical design is flawed.
Based upon public comments to this notice and on information
already available and outlined in this notice, the Board will consider
whether it is appropriate for ADAAG to include criteria for such
acoustical performance characteristics as reverberation time and
background noise. Several non-rulemaking options will also be
considered, including additional research, the development of advisory
materials, and guidance and technical assistance for design
professionals.
In response to the petition, the Board wishes to focus this request
for information on the acoustical performance of classrooms and related
spaces used by children, including day care settings for pre-primary
ages. However, the Board will consider comments and recommendations on
the scope and technical provisions of acoustical criteria appropriate
for buildings and facilities and other occupancies, as well.
The Board seeks relevant research, standards, data, test reports,
analyses, and recommendations from acoustical engineers and
consultants, design professionals, educators and educational
administrators and counselors, audiologists, specialists in hearing
impairments, parents of children with disabilities and persons with
hearing, speech, and language disabilities, including learning and
developmental disorders, and the organizations that represent them.
Commenters are encouraged to address their responses to the issues
outlined below.
Question 1: Implementing acoustical guidelines in educational
facilities for children may be necessary for youngsters with auditory
and related disabilities to function effectively in school. (a) Should
all rooms and spaces within a school setting be included in coverage?
Some comment has identified gymnasiums, pools, and cafeterias as
particularly problematic for students with hyperacusis, a heightened
sensitivity to noise, and for those with learning and auditory
processing disabilities. Such facilities are often highly reverberant
due to their large areas of hard, sound-reflective surfaces. (b) Should
acoustic guidelines include coverage of these spaces? Would a less
stringent standard be appropriate in non-classroom school facilities?
What acoustical properties are appropriate in multi-purpose spaces that
accommodate recreation, performance, and food service activities at
different times during a school day? (c) In view of the importance of
early language acquisition, how should child care settings be covered?
Are there acoustical criteria in current health and safety standards
for child care facilities? (d) Should the Board consider the
development of guidelines for a wider range of facility types for a
more universal range of users? If so, what facilities might be
included?
Question 2: The Board has received information on several cases in
which the acoustical environment was an issue in an Individualized
Education Plan prepared by a school system for a child with a hearing
impairment. Would a common standard for the acoustical design of
educational facilities be helpful to design professionals seeking to
provide acoustically satisfactory environments and to school systems
seeking to comply with educational mandates for children with
disabilities? Are current design manuals, recommendations, and other
technical assistance on acoustical design sufficient?
Question 3: There is considerable research that shows that
controlling classroom noise and reverberation will benefit student
learning. However, it is not clear at what levels effective listening
by children with mild, moderate, severe, or profound hearing losses and
other disabilities is compromised and whether such conditions can be
achieved in some classroom environments, where ``self-noise'' and
student activity also contribute to a poor listening environment. (a)
Is there research that identifies the specific acoustic requirements
necessary for effective listening by children with various hearing,
speaking, and learning disabilities? What acoustical performance and
testing standards are appropriate for classrooms in which children with
auditory disabilities are integrated? Are there data that relate
specific acoustical criteria to the usability of buildings and
facilities by children with learning disabilities, developmental
disabilities, and other disabilities that affect speech reception,
learning, and communication? (b) What are the relative contributions of
low reverberation values and low background noise values to effective
communication for people with hearing loss? (c) Can the acoustical
environment be improved sufficiently through design and construction
measures for children with hearing and other impairments to receive
significant communications benefit?
Question 4: The Board also seeks information on the acoustical
environment necessary for effective use of assistive technology,
including hearing aids and assistive listening devices, by children
with hearing loss. Because assistive technologies will be part of many
student accommodations, the Board is interested in the extent to which
poor acoustics compromise the effectiveness of technologies such as
sound field enhancement (in which the amplified voice of a teacher
fitted with
[[Page 29684]]
a microphone can be distributed to speakers placed around the perimeter
of a classroom) and direct broadcast to children with hearing loss
through personal assistive listening devices. At what thresholds of
background sound and reverberation will children with various degrees
of hearing loss be able to participate in meaningful classroom
listening if aided by amplification technology?
Question 5: The GAO report on school conditions highlighted the
multimedia classroom as the educational facility of the future. The
Board is interested in understanding the nature and characteristics of
such a classroom, particularly the extent to which it may be
interactive, with small group listening and discussion, multiple inputs
from speakers and media devices, frequent changes in speaker-listener
relationships, and other audio source conditions that may not be fully
adaptable to amplification technologies.
Question 6: The Board recognizes that decisions made by building
design professionals during the design phases of a project affect the
ultimate acoustical performance of a room or space. Determinations of
building siting, overall facility planning, and individual room volume
and proportion, floor, wall and ceiling assembly construction and
finishes, equipment specification, and HVAC system design all
contribute to the acoustic functioning of a room or space. However,
most recommendations for acoustical performance measure the results of
such design decisions, setting limits on reverberation and background
noise. (a) Can good speech listening conditions be achieved by setting
standards for reverberation time and background noise only? (b) Should
other design variables, for example, room configuration or proportion,
ceiling height, or size, be considered? The Swedish guidelines specify
wall and ceiling construction types and values in addition to limiting
background noise. Are these a useful model for possible guidelines? (c)
How might considerations of speech intelligibility, speech transmission
indices, and other measures that rely on in-use testing be incorporated
in acoustical design? What are the margins of error in acoustical
equipment, testing, simulation, and construction? (d) What are
effective means of acoustically retrofitting an existing classroom or
other space that performs poorly for speech perception? How successful
can such corrective action be in correcting perceived hearing and
listening problems?
Question 7: What is the square foot cost for new classroom
construction today? What additional square foot cost would be necessary
to meet average industry recommendations for reverberation time (R
.6--.8 seconds) and background noise (NC 35-40) for classrooms? What
would be the added cost, per square foot, of achieving values within
the ranges suggested by ASA (R .4--.6 seconds; NC 25-30)? What are the
relative costs of meeting reverberation limits as opposed to background
sound limits? What data are available on the costs of alterations to
existing environments to improve acoustical conditions?
Question 8: The Board also seeks information on the non-capital
costs and savings associated with constructing and maintaining
acoustically-appropriate classrooms and related educational facilities.
What are the cost implications of such design and finishes decisions
and operating procedures as room location and configuration, window
operability, and carpeting? What savings might accrue from the
elimination of some special education environments?
Question 9: How can compliance with acoustical design criteria be
assessed prior to facility occupancy and use? How can time and physical
variations in equipment manufacture, construction, and outside noise
conditions be accommodated in a guideline? What testing and compliance
practices have been used where standards are already in place?
Question 10: Many teachers and administrators have had experience
with open classrooms, in which several teaching groups may work
concurrently in a single large space, and with enclosed classrooms of
smaller size. (a) The Board is particularly interested in comments
offering a comparison of the effects on students and teachers, in
particular those with disabilities, of classroom acoustics in such
situations. (b) Do noisy classrooms exacerbate teacher stress? Are
there data available on the effects of classroom noise on teacher
health, comfort, or performance? (c) Do schools and systems have
information on student behavior and performance after acoustical
improvements, including the partitioning of open classrooms into more
discrete units, have been made?
Question 11: What approaches other than regulation under the ADA
might be successful in achieving good acoustical design? What
organizations and interests should be consulted in the Board's
consideration of acoustical issues?
Dated: May 26, 1998.
Thurman M. Davis, Sr.,
Chair, Architectural and Transportation Barriers Compliance Board.
Table 1 on recommended/required acoustical criteria for classrooms
follows:
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[FR Doc. 98-14442 Filed 5-29-98; 8:45 am]
BILLING CODE 8150-01-C
