Classroom Acoustical Requirements

Research has shown that all young children are affected by background noise in the classroom. In addition, young children also have more frequent ear infections and fluid in the middle ear which can affect understanding directions, learning to read and making social connections. Children who are deaf or hard of hearing have even more challenges. Hearing aids and cochlear implants amplify all sounds which make it difficult to filter background noise. Background noise includes sound bouncing off hard floors and walls, noise from the street, and fans running for heating or cooling as well as low-level chatter. 

The average American student with normal hearing can only understand 75% or less of what is being said when they are in a classroom that is not designed with improved acoustical standards. In addition, 90% of students seated in the back of a classroom with poor acoustics can understand their teacher at the front.  

When you consider that children are still developing language, having them try to understand their teacher's voice in noisy environments has a negative impact on their learning experience. Background noise has an even more significant effect on access to spoken language for children who are deaf, deafblind or hard of hearing, so special care needs to be taken to lower background noise with good acoustics.

Who this impacts

  • Students who are deaf, hard of hearing or deafblind, including those who may or may not use hearing aids, other hearing assistive technology devices and systems, and cochlear implants
  • Children with one-sided (unilateral) hearing loss
  • All students, especially those in the early elementary years, when ear infections and lingering fluid is more common
  • School teachers, including those in general and special education classrooms

Solution

The Minnesota Commission of Deaf, DeafBlind and Hard of Hearing has long recognized the acoustic challenges that affect all children in classrooms but especially deaf, deafblind and hard of hearing students.  The Commission shared scientific research from the American National Standards Institute (ANSI) and the Acoustical Society of America (ASA) with legislators to inform districts when schools are planning new construction or renovations.  In 2004, the Commission supported the adoption of the National Access Board and American Standard Institute Classroom Acoustic Standards by the Minnesota Department of Education for new school construction.  The following year, the Commission successfully advocated for a law that requires school boards to consult acoustic standards when creating designs for new classrooms.  This rule is found under Minnesota Statutes, Section 123B.71, Subd. 9, (6) (iv) and is in reference to the ANSI/ASA standard on maximum background noise levels (35 dB) and reverberation times (0.6 seconds or less).  The standard includes noise produced by heating, ventilating, air-conditioning systems, building services, and outside noise such as traffic.  This law is current for all new construction and renovations in school buildings.  

Infographic on classroom acoustics

Due to the COVID-19 pandemic, schools have been updating their HVAC systems to meet healthy air standards. The Commission, in partnership with Cheryl Johnson AuD, Sarah Schraufnagel, AuD, and Peggy Nelson, PhD, developed two infographics on classroom acoustics. One infographic is specifically for Minnesota. The other is for other states. 

  1. Minnesota Classroom Acoustics infographic (PDF)
  2. National Classroom Acoustics infographic (PDF)

Who was involved?

  • Julie Edleman
  • Mary Hartnett
  • Peggy Nelson, Professor of audiology in the Department of Speech-Language-Hearing Sciences at the University of Minnesota
  • Mike Nixon, a hard of hearing acoustical engineer
  • Rhonda Sivarajah, parent
  • P.J. Wilson, student
  • Andrew Palmberg
  • Cheryl Johnson, AuD
  • Sarah Schraufnagel, AuD
  • Anna Paulson, EdD
 
Mike Nixon's advocacy for classroom acoustics
Length: 4:55 Direct Link
A shining example.

Transcript

Mike Nixon, a hard-of-hearing acoustical engineer, was a passionate crusader for good acoustical environments in schools. He served on a national board to develop school standards for acoustics that were endorsed by the U.S. Access Board.

Despite a wealth of solid research on the negative impacts of noisy classrooms, the results had been ignored by local school districts. Just as a lack of ramps and narrow doorways presented architectural challenges for wheelchair users in schools, noisy classrooms presented similar barriers to learning for all children. Nixon said at the time, "We put kids in classrooms where they can’t hear, but we’d never put them in a classroom with the lights turned off."

Nixon wanted to make a difference on a local level. In 2001, he approached [the Commission] for help introducing a bill requiring all newly built schools in Minnesota to adhere to the U.S. Access Board standards. Nixon visited key legislators, attended every hearing and gave expert testimony, even though he was weak from chemotherapy treatments. Dr. Peggy Nelson, of the University of Minnesota, had served on the national committee with Nixon. Rhonda Sivarajah, a hearing mother of a deaf son, and P.J. Wilson, a deaf student, joined Nixon in his crusade.

At the final hearing on the bill, the FM system in the legislative hearing room wasn’t working so Nixon couldn’t hear. Soon, the sound system also failed, making it difficult for everyone to hear. Legislators only heard every third word, similar to how much information children miss in classrooms with poor acoustics. The bill’s chief author said, "Ladies and gentlemen, this is exactly what kids experience in a classroom when acoustics are bad." The bill passed.

Thanks to Mike’s work, all new schools in Minnesota must incorporate these standards.