December 1997 Workshop on Acoustics and Learning


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This volume contains the Proceedings of the ASA-organized Workshop on ELIMINATING ACOUSTICAL BARRIERS TO LEARNING IN CLASSROOMS held at the House Ear Institute, Los Angeles, California on Dec. 6,7, 1998. The Proceedings consist of the unmodified material presented at the Workshop. The format is consistent with the informal nature of the Workshop.

 The Workshop was designed to bring together people engaged in planning, development or use of educational facilities:

Educators Speech Pathologist

Administrators Acousticians

Architects Government Officials

Audiologists Concerned Parents

 to address the issues research has confirmed that poor classroom acoustics (high noise levels or reverberation):

  o create a major barrier to individual learning;

  o place additional burdens on teachers;

  o cause low student achievement, poor classroom discipline and teacher burnout;

  o is detrimental to all students and teachers but especially to those with a hearing, learning or language disability;

  o and can be avoided by design and corrected in a cost effective manner with current knowledge when applied in a timely fashion.

  The Workshop was designed to provide background on the nature and scope of the problems caused by bad acoustics in classrooms and outline practical planning strategies and methods to avoid or correct bad acoustics in existing or planned educational facilities.


The major presentations made during the workshop, which are included in various forms, are briefly summarized as follows.

Keynote Speaker, Dr. Robert Apfel, Yale University, Dr. Apfel's talk entitled: "Classroom Communication or Classroom Chaos - The Choice is Ours" focused on the overall challenges of the workshop to the educational facility designers and users. He illustrated his points with a chart showing the proper trade off between noise energy and reverberation that must be made in a classroom to maintain good intelligibility.

Workshop Structure - Goals & Objectives, Jim DuBois reviewed the goals and objectives of the workshop as summarized in the charts for his section and as noted above.

Technical Aspects of Classroom Acoustics, David Lubman provided a short introduction to the basic concepts and terminology in acoustics appropriate for understanding the problems to addressed in the workshop. This was followed by a short demonstration, with the assistance of Mark Schaffer of various levels of background noise that can occur in a classroom from several sources, primarily heating or air conditioning systems.

Students at Risk, Dr. Sigfrid Soli lead off this session introducing the three speakers: Donna Sorkin, Peggy Nelson and Karen Anderson. Ms. Sorkin, in reviewing the student population at risk in noisy classrooms, provided a very simple but highly effective demonstration of the progressive difficulty in understanding words in the presence of noise or with simulated hearing loss using ear plugs. Peggy Nelson developed the data on the numbers of students a risk in more detail and the causes for this risk, emphasizing the importance of various forms and prevalence of hearing disorders. Karen Anderson, as an Education Audiologist, stressed the importance of interaction between school officials and school audiologists and presents, in her reprint paper, the challenges to the former to work towards developing quieter classrooms.

Robert Donald, Deputy Director of the Design and Inspection Branch of the Los Angeles Unified School District, was the luncheon speaker. Although his remarks are not included herein, he reviewed the major obstacles and progress he and his staff have made in the ongoing implementation of a major program to add large window-type (or wall-mounted) air conditioning systems to LA schools. The biggest challenge is to obtain sufficiently quiet units for use in classrooms. Although much progress has been made, thanks to a large extent to the diligence of Mr. Donald's staff, so far, manufacturers are not able to fully meet the desired noise level criteria. However, he expressed that further market pressure should improve this situation and committed to including proper noise criteria in specifications for new classrooms for LAUSD.

Acoustic Design Regulations, Guidelines & Standards, Louis Sutherland led off this session with an introduction of the other speakers: Dr. Joseph Smaldino, Mark Schaffer, Daniel Bruck and Lois Thibault. Dr. Smaldino reviewed the Position Statement and Guidelines on classroom Acoustic criteria developed in 1994 by the American Speech-Language-Hearing Association. These called for a limit on background noise levels of 30 dB(A), a signal to noise ratio at the student's ear of 15 dB and a reverberation time of 0.4 sec.

Mark Schaffer reviewed similar guidelines, included later under his presentations for the Problem Solving Clinic, proposed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Daniel Bruck presented a summary of criteria developed for the Seattle School District (not shown herein) and also presented a case history of a before-and after treatment for a particularly bad classroom acoustics problem which his firm had solved.

Lois Thibault, as a spokesperson for the U.S. Architectural and Transportation Barriers Compliance Board (the Access Board) under the U.S. Dept. of Justice classrooms, presented a very thorough review of the Access Board rule making process and mandates dictated by the "Americans With Disabilities Act" emphasizing those aspects that relate to the objectives of this Workshop. Her presentation included considerable detail which is included herein under this section on Acoustic Standards.

Louis Sutherland presented an overview of available International Standards on classroom acoustics from Sweden, Germany and Portugal. The latter two specify performance standards similar to the ASHA Guidelines. The Swedish Standards are in a mixed form with use of a matrix of sound isolation (performance) criteria between various types of spaces in a school and a simple design standard for reverberation - the latter offering an advantage for application in terms of simplicity and ease of implementation.

Panel - Overview of Solutions, Prior to starting the break-out sessions, Jim DuBois led a panel consisting of Roberta Null, Ann Seltz, Mark Schaffer and Ewart (Red) Wetherill to provide an overview of solutions to the elimination of acoustic barriers to learning in the classroom. The informal discussion, not included in these proceedings, provided an overall background summary to assist in guiding the breakout sessions.

Breakout Sessions Five groups of about 10 people per group addressed the following questions.

1) How can acousticians, architects and audiologists work effectively with administrators teachers, students and parents to create acoustically excellent learning spaces?  

2) What do you see as being the problems: administrative, architectural, engineering, financial, political (or legislative)?

3) What are your recommendations for solutions to the problems, for actions to take, and who should be responsible?

Following these breakout sessions, the moderators for each group presented their group's findings - these are included herein in the same informal manner in which they were presented. They are not summarized here since they have been boiled down to the overall Workshop findings presented later.

At this point, the attendees broke for a much-deserved social hour, including, for some, a tour of the research facilities of the host organization, the House Ear Institute.


Clinic on Noise Control Options. Starting off the second day of the workshop, Mark Schaffer presented a problem-solving clinic on noise control for HVAC systems and summarized recommended design and performance criteria for such systems suitable for application in classrooms. His material ends with a sample Procurement Specification for the type of wall-mounted HVAC (Heat Pump) unit being procured by the LAUSD. The specification employs terminology well understood by the specialists in this field including manufacturers of such units.


Classroom Audio Amplification Systems, Joseph Smaldino presented a detailed summary of the issues and criteria to define when use of sound field amplification systems is an appropriate supporting technique to augment good acoustic design for HOH students who require optimum acoustic conditions that can not always be provided in a passive acoustically-well-designed classroom space. The issues are complex and are reviewed in considerable detail in this section.

Advantages & Disadvantages of Alternative Solutions, Dave Lubman led a panel discussion on this topic including informal presentations by Mark Schaffer, Joseph Smaldino and Ewart (Red )Wetherill. (Regrettably, the very informative "chalk talk" presented by Red was not available for incorporation in these proceedings.)

Multimedia and Classrooms of the Future, Dr. Dean Heerwagen presented an overview of some of the concepts in multimedia communication systems being explored by him and his colleagues at the University of Washington. Some of these concepts by his colleagues are included herein. (It is likely that this futuristic aspect of classroom acoustics will become much more important in the future and should probably receive more emphasis than time permitted at this workshop.)

Organizing Committee Report on Breakout Sessions, Jim DuBois presented the Committee report. Thanks to the work of the workshop organizers and, especially the logistics support of our host, Dr. Sig Soli, the charts summarizing the breakout session findings were developed in the polished form included this section.

The reader is strongly encouraged to read these charts in total. Some of the key points presented in these charts are:


- Form a Coalition.

- Raise Public Awareness through a targeted media blitz




- Ignorance of the problem abounds.

- Cooperation needed between diverse groups.

- Financial obstacles are severe.

- Standards needed.


- Develop simple guidelines and standards NOW.

- Develop a consortium of groups for action in a Coalition.

- Identify funding sources.

- Develop checklists, info care packages, recognition systems.

- Maintain on-going public education activity.

- Submit position statement to Access Board.


In response to the above action plan, a draft of a Mission Statement and Objectives for a Coalition on Classroom Acoustics has been prepared and this is contained at the end of this Organizing Committee Report section.

Following the close of the workshop, Michael Nixon introduced several researchers in the field who made informal presentations of their work. One of these presentations, which outlines ongoing research, is represented by material contained herein from:

Dr. Murray Hodgson, University of British Columbia, Canada

Also included herein is material from a Poster session held during the Social Hour in Saturday evening that was submitted by Drs. Sharon Airey, David MacKenzie and R.J. Craik, Heriot-Watt University, Edinburgh, Scotland and presented in the Poster Session by Dr. Airey.


At the end of these Proceedings, two Appendices contain:

A. A brief report on environmental conditions of the nation's schools based on a recent U.S. General Accounting Office report. This report showed that an estimated 28% of the schools judge "acoustics for noise control" as the dominant "unsatisfactory or very unsatisfactory" environmental factor in their schools.

B. List of potential participants or supporters of the Coalition developed at the end of the Workshop.