Acoustical Performance Criteria Research Articles

Comparison of reverberation times and average absorption coefficients in classrooms, based on in situ measurements versus calculated from material databases as during design

Reverberation time (RT) is an acoustic descriptor used widely by acousticians for characterizing indoor acoustic environments, as specified in standards such as ANSI S12.60 “Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools”. It is often calculated in the design phase for simple spaces by applying equations like Sabine’s or Eyring’s, requiring information on room dimensions and the surface areas and acoustic absorption coefficients across frequency of room materials. In this project, measured RTs from a recent survey of over 200 K-12 classrooms are compared against the RTs predicted across speech frequency octave bands using Sabine’s and Eyring’s equations. Agreement between predicted and measured values varies based on the octave band and material selection. The working group currently revising ANSI S12.60 is considering providing guidance on the desired average absorption coefficient in classrooms, rather than reverberation time, so this study also compares the average absorption coefficients for the classrooms. The coefficients are back-calculated from the measured RTs using Sabine’s and Eyring’s equations, and compared against those calculated from surface dimensions and commonly available material absorption coefficients.

Background noise and reverberation time in a college classroom

A sound survey of noise levels in unoccupied classrooms on the Marietta Campus of Kennesaw State University identified one classroom as the most problematic in terms of background noise levels. This level is mostly associated with heating, ventilation, and air-conditioning equipment. Excessive background noise in learning spaces diminishes the speech intelligibility from the speaker to the listeners and can cause stress and fatigue. The overall A-weighted average sound levels are compared with ANSI-ASA S12.60-2010/Part 1 (Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools). In addition, frequency analysis of the background sound and time variations are studies. Binaural headset microphone measurements are compared to the single microphone measurements. Reverberation time is measured using the engineering survey method and compared to the ANSI guidelines.

Survey of background noise levels inside classrooms on a college campus

Sound level measurements were made for 18 classrooms and learning spaces on the Marietta Campus of Kennesaw State University, Georgia, USA. Excessive background noise in learning spaces diminishes the speech intelligibility from the speaker to the listeners. The noise measured was in empty or nearly empty classrooms with no one talking. The primary background noise source was observed to be due to heating, ventilation, and air-conditioning equipment. The results are compared with a student survey to see if the noise complaints correlate with the noisiest classrooms in terms of their average A-weighted decibel levels. In addition, conformance with ANSI-ASA S12.60-2010/Part 1 (Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools) is evaluated.

In-Progress Updates to ANSI S12.60 Part 1 Pertaining to Building Sound Isolation

In early 2022, work began to update ANSI/ASA S12.60, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools—Part 1 Permanent Schools. The current version of this standard is from 2010. When the working group was polled for comments and requested changes for a new version of the standard, concerns regarding how the 2010 version handles building envelope sound isolation requirements were numerous. The current progress of the working group’s actions regarding modifications to the standard’s building envelope sound isolation language will be discussed.

Sound Transmission Guidelines in Mass Timber Schools; Meeting ASA/ANSI S12.60-2010

In recent years, the education sector has begun to turn to mass timber for new construction and expansions of schools. There are several reasons that make mass timber well suited for the education sector with seismic resistance and faster construction timelines being two major drivers. ANSI/ ASA S12.6 Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools is often used as the standard for school design and adequately addressing sound transmission between learning spaces. This analysis looks at mass timber assemblies that meet the ANSI/ ASA S12.60 guidelines. ASTM E336 and ASTM E1007 testing post construction was completed to evaluate in situ performance for comparison to the design guidelines.

Classroom mock-up meeting Standard S12.60

The Acoustical Society of America (ASA) developed a standard entitled Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools (ASA/ANSI S12.60-2010) that provides a minimum set of requirements to help school planners and designers “provide good acoustical characteristics for classrooms and other learning spaces in which speech communication is an important part of the learning process.” In this revision, several details were revised for incorporation into building codes. Despite the obvious benefits of quieter classrooms, incorporating the standard into building codes met with resistance. A common perception was that in order to meet the standard’s requirements, specialized HVAC equipment and installation methods would be necessary, resulting in an installed cost beyond what most schools could afford. Acoustical prediction tools indicated that the requirements could be met using standard HVAC equipment and installation methods. To verify the predictions, a simulated classroom was built and several common types of equipment including a single-zone air handling unit, a high-efficiency water-source heat pump, and a packaged rooftop unit were tested. The selected products were standard catalog offerings, without any special attenuation features, that were operated at typical airflow and static pressures. This paper describes those tests, the conclusion, and the resulting recommendations.

Framework to manage railway noise exposure in Brazil based on field measurements and strategic noise mapping at the local level

Rail freight transport has grown worldwide and in Brazil as well, which increases people's exposure to railway noise. A promising tool to manage it is Strategic Noise Mapping (SNM), which has advanced around the world favoring a common and more accurate calculation method that requires more accurate measurements. This paper presents a framework to manage railway noise exposure in Brazil based on a case study carried out in the city with the longest stretches of railway tracks in urban areas. Background noise due to road traffic and train pass-by noise levels were measured for knowledge of noise sources and SNM calibration. Background noise predicted by the CNOSSOS-EU (Road) method reached an accuracy within ±2 dB(A) and was overestimated by the NMPB-96 method. The combination with railway noise using the SRM II and ISO 9613 calculation methods maintained the aforementioned accuracy, while the current best fit CNOSSOS-EU (Railway and Industry) configuration for the study area overestimated it. Although the study area is a quiet suburb, a quarter of its population is exposed to road traffic noise levels above those recommended by WHO, and more than 40% are affected by rail noise that is 5 dB(A) or higher than the background noise. The elimination of level crossings (LC) and the need to sound the train horn is more cost-effective than noise barriers. Therefore, the strategy to manage exposure to rail noise in Brazil should involve altering residential zoning of non-built-up areas next to the railways to repurpose them for other land uses and/or establish acoustic performance criteria for new buildings; federal government investing in reducing the number of LC or railway variants; and railway operators investing in the creation of an emission database for noise control at the source.

The evolution of standard S12.60 acoustical performance criteria, design requirements, and guidelines for schools

The committee on standards for the Acoustical Society of America was asked by the US Access board and others to develop standards for acceptable acoustics in classrooms. The effort resulted in a standard comprised of several parts. The first document was approved in 2002 and this later became part 1. The initial desire was to have a federal rulemaking and incorporate the standard into coverage for the Americans with Disabilities Act. Part 2 was approved in 2009 and provided guidance for relocatable learning spaces. The intent to have a federal rulemaking was thwarted by political factors so Part 1 was revised in 2010 with the intent to put the document into a format that would allow its incorporation or use in building codes. Part 3 is still being developed, but it is intended for Information Technology Equipment in Classrooms. Part 4 was approved in 2019 and gives guidance for education spaces such as gymnasia and other spaces used for physical education.

Assessment of Acoustical Performance of Residential Buildings for Sustainable Liveability and Satisfaction in Awka, Anambra State Nigeria

This study assessed the acoustical performance of residential buildings in Awka, Anambra State to determine the level of satisfactions of the occupants. The study surveyed the residential buildings and distributed questionnaires to the users and occupiers of different classes of residential buildings. The results of the survey were analysed using Means Satisfaction Index (MSI) and Relative Performance Index (RPI) to assess the level of satisfaction of the occupants of the buildings and the acoustical performance of the buildings respectively based on 12 selected acoustic performance criteria. It further used Pearson Product Moment Correlation to establish the relationship between occupants’ level of satisfaction and acoustic performance of the buildings. The study found that the overall acoustic performance of the buildings was grossly poor and unsatisfactory with average RPI of 0.35. It also found that the residents were very dissatisfied with the acoustic performance of the buildings in which they live (average MSI =1.74). The study further found that there was significant positive relationship between the occupants’ level of satisfaction and acoustic performance of the buildings with a Coefficient Correlation (r) of 0.875 and a computed t-test value of 5.708 which is greater than the critical t- value (2.228) tested at 5% significance level. The Coefficient of Determination (R2 = 0.7567) then suggested that about 75.69% level of satisfaction of the occupants of the residential buildings in Awka could be triggered by the acoustic performance of the buildings in which they live. On this evidence, the study craves for the enforcement of the provisions of the National Building Code as regards to sound control in buildings. In addition, there is need for adoption of different strategies for improving acoustics performance of buildings such as absorption, mechanical decoupling, mechanical damping, blocking, covering, etc., so as to promote good acoustic practices that would improve sustainable performance of our buildings and decline the resulting consequences of sounds in our residential buildings.

Experimental study of acoustic performances of reactive engine mufflers

A well designed muffler means a compromise between its acoustic performance, backpressure, size and cost criteria. The acoustic performances of engine mufflers, in terms of insertion loss (IL) constitute the major aim of this paper. An experimental investigation of two manufactured mufflers with different inner configurations is realized. Insertion loss investigation is performed in an anechoic room and the experimental setup agrees the ISO 7235:2009 requirements. The analysis in third-octave band of measured noise gives us the sound pressure level on each frequency of interest. Sound attenuation and pressure results are highlighting the influence of mufflers inner configurations on their acoustical behaviour. A FEM analysis completes our study and simulations based on pressure results are performed in order to evaluate the critical displacements correlated to vibration eigenmodes. Our manufactured mufflers realize a good sound attenuation depending of their internal configuration.

Acoustical design for libraries in schools to comply with ANSI S12.60

In K-12 schools, the library functional space is now usually called the media center, as this space houses and disseminates information that is stored on both print and digital media. These spaces have fewer sound absorbent book stacks than were found in previous print-only libraries. Instead, computer workstations for student access to local and web-based material are provided. Often these facilities are used as group learning spaces, with several group classes occurring simultaneously. These changes to the traditional school library space present challenges to the acoustical design. Another challenge is that in a number of school districts across the US, a media center must be designed to meet the requirements of ANSI/ASA 12.60-2010/Part 1, “American National Standard Acoustical Performance Criteria, Design Requirements and Guidelines for Schools, Part 1: Permanent Schools,” also known as the “Classroom acoustics standard.” This is because a media center can be defined as a core learning space that is subject to that standard, with its requirements for low noise and reverberation, and for higher sound isolation from adjacent spaces. Several case studies are presented which highlight the design challenges for modern school media centers, and the successful design solutions.

Impact and revision of UK legislation on school acoustics

Since 2003 new school buildings in England and Wales have been subject to Building Regulations which impose a legal requirement for spaces in schools to meet acoustic performance criteria for ambient noise levels, reverberation times and sound insulation. The criteria are specified in the Department of Education publication ‘Building Bulletin 93’ (BB93). In 2008 it was agreed that BB93 would be updated. The Labour government endorsed the need for good acoustic design of schools and agreed to a minor revision of the legislation. However, the new government elected in 2010 recommended the removal of legislation on school acoustics, in order to reduce the cost of new school buildings. The acoustics community in the UK successfully lobbied the government to keep the legislation and it has been agreed that the acoustic regulations relating to the performance of a building in use will be retained. BB93 is currently (June 2012) being redrafted and the acoustic performance specifications revised. This paper will use the results of a recent large scale survey of the acoustics of secondary schools in the UK to examine the impact of BB93 on school design over the past 10 years, and will discuss the current revision of the legislation.

Music rehearsal room acoustics: comparisons of objectives and performance measures

A comparison of the acoustic performance criteria for high school music education rehearsal rooms to standard classrooms in the United States and Asia. High school music rehearsal rooms have acoustical requirements that are very different from traditional classrooms, where academic subjects are typically taught in a lecture-based setting. Due to the extended frequency range and dynamics of music rehearsals, most standard classroom acoustic treatments will not provide effective results for music rehearsal rooms. A number of acoustic measurements will be discussed – comparing rehearsal rooms and standard classrooms. Potential problems and solutions will be identified.

Ambient noise levels and reverberation times in Mississippi school rooms.

Nine elementary school classrooms at three Mississippi public schools were selected at random for noise and reverberation time measures to monitor voluntary compliance with ANSI standard S12.60‐2002 (Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools). 1‐h equivalent dBA noise levels and reverberation times (T60) were measured with SPECTRAPLUS Version 5.0 software. Measures were taken on separate days at each school in unoccupied classrooms with the HVAC system operating. For ambient noise measures, an Audix TR40 omnidirectional microphone was placed in a 12 in. stand on a student’s desk near the middle of the room and oriented toward the teacher’s desk at a 45 deg angle. For the reverberation time measure a 400 W loudspeaker (Yamaha BR15M) was placed on the teacher’s desk about 3 m from the microphone. Results showed that noise levels varied from 28 to 51 dBA with broad spectra containing peaks at 120 Hz and harmonics. Five of nine classrooms had noise levels that exceeded the ANSI recommended level of 35 dBA. Reverberation times varied from 0.21 to 0.62 s; only one classroom exceeded the recommended minimal reverberation time of 0.6 s. Acoustical modifications to reduce noise levels and reverberation times will be addressed.

House Committee Passes Student Loan Bill

You have accessThe ASHA LeaderPolicy Analysis1 Sep 2009House Committee Passes Student Loan Bill Neil Snyder Neil Snyder Google Scholar More articles by this author https://doi.org/10.1044/leader.PA1.14112009.1 SectionsAbout ToolsAdd to favorites ShareFacebookTwitterLinked In The Education and Labor Committee of the U.S. House of Representatives considered and passed H.R. 3221, the Student Aid and Fiscal Responsibility Act of 2009, which reorganizes the entire student loan industry. The legislation states that all student borrowers must get direct loans from the U.S. Department of Education rather than from other private industry lenders, such as Sallie Mae, Wachovia, or local banks. The bill would eliminate federally subsidized and guaranteed private-sector loans—about 60% of all student loans—at a savings estimated at $100 billion over 10 years. These savings would be redirected to other programs, including Pell Grants for students meeting income eligibility requirements. Lawmakers are at odds over whether or not the bill will benefit students seeking college loans and grants. According to a statement from George Miller (D-Calif.), Education and Labor chair, “The legislation…will generate almost $100 billion in savings over the next 10 years that will be used to boost Pell Grant scholarships, keep interest rates on federal loans affordable, create a more reliable and effective financial aid system for families, and enact President Obama’s key education priorities.” However, a press statement from Rep. John Kline (R-Minn.), ranking minority member of the committee, maintains that “The Democrats’ legislation, H.R. 3221, abolishes the Federal Family Education Loan (FFEL) program and redirects tens of billions in government savings and earnings toward new entitlement programs that do not directly benefit low-income students’ pursuit of higher education.” Noise Reduction Of particular interest to ASHA members is a provision in the bill that would direct $5 billion in estimated loan program savings to fund the 21st Century Green High-Performing Public School Facilities Act (Section 345). This act has already been passed—but not funded—by the Education and Labor Committee and the House of Representatives. This “green schools” act would allow states and school districts to use federal funds to reduce or eliminate exposure to classroom and environmental noise and would also encourage the use and compliance with the American National Standards Institute (ANSI)-approved Standard S12.6–2002, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools. The legislation passed the committee along party lines by a vote of 30–17, with two Republicans voting in favor of the bill. It will now go to the full House, which will not consider it until after its August recess. It will not be considered by the Senate until later in the fall. In a separate but related issue, Rep. John Tierney (D-Mass.) offered—but withdrew—an amendment that would have provided automatic funding for a federal student loan forgiveness program that includes school-based speech-language pathologists and audiologists. This program has been authorized, but not funded. Rep. Tierney agreed to work with Rep. Miller to request funding for the program through the regular appropriations process. Author Notes Neil Snyder, director of federal advocacy, can be reached at [email protected] or 800-498-2071 ext. 5614. Advertising Disclaimer | Advertise With Us Advertising Disclaimer | Advertise With Us Additional Resources FiguresSourcesRelatedDetails Volume 14Issue 11September 2009 Get Permissions Add to your Mendeley library History Published in print: Sep 1, 2009 Metrics Downloaded 75 times Topicsleader_do_tagleader-topicsasha-article-typesCopyright & Permissions© 2009 American Speech-Language-Hearing AssociationLoading ...

Congress Acts on Classroom Acoustics

You have accessThe ASHA LeaderPolicy Analysis1 Jul 2009Congress Acts on Classroom AcousticsFederal Officials Learn More About the Issue at ASHA Briefing Neil Snyder Neil Snyder Google Scholar More articles by this author https://doi.org/10.1044/leader.PA1.14092009.6 SectionsAbout ToolsAdd to favorites ShareFacebookTwitterLinked In In the span of one week, ASHA enjoyed two significant Capitol Hill successes to promote better classroom acoustics. The House passed legislation that allows federal funds to be used for acoustic improvements and ASHA hosted a briefing attended by more than 50 congressional staff, federal agency representatives, organizations representing people with hearing loss, and a contingent of ASHA audiologists. Public School Improvements Panelists at the classroom acoustics briefing included (from left) 12-year-old Nicole Hubert and her father, Greg; ASHA member Peggy Nelson, professor of audiology at the University of Minnesota; architect Marcus Adrian; and Elizabeth Stewart from the United States Access Board. On May 14, the U.S. House passed H.R. 2187, the 21st Century Green High-Performing Public School Facilities Act. This legislation requires the secretary of education to make $6.4 billion in grants available to states for the modernization, renovation, or repair of public schools (including early learning facilities and charter schools) to make them safe, healthy, high-performing, and technologically up-to-date. H.R. 2187 would authorize the grants for fiscal year 2010 and beyond. H.R. 2187 includes provisions that allow school districts to address classroom noise and acoustics in school buildings. The bill now goes to the U.S. Senate for further consideration. ASHA has been working for several months with several congressional offices to improve and expand schools’ abilities to address excessive classroom noise and poor acoustics. H.R. 2187 is similar to legislation considered in 2008 (H.R. 3021) and adds provisions allowing federal grants to be used by school districts to take “measures designed to reduce or eliminate human exposure to classroom noise and environmental noise pollution.” During consideration of H.R. 2187 in the House Education and Labor Committee, Rep. Joe Sestak (D-Pa.) offered a two-word amendment allowing schools to use money on “ceilings [and] flooring,” key elements in addressing building noise and acoustics. In remarks on his amendment, Sestak indicated that he was late to the committee mark-up session because he had been meeting with his daughter’s audiologist. His daughter is recovering from brain surgery and is receiving chemotherapy, which has caused hearing loss, he explained. Sestak further noted that his congressional district is on the flight path of Philadelphia International Airport, where planes fly as low as 500 feet. He has received reports of children not being able to hear in their classrooms and has been working with the Federal Aviation Administration on noise abatement. ASHA also worked with Rep. Carolyn McCarthy (D-N.Y.) to include language on acoustical standards in the bill’s report, encouraging school districts to undertake projects “to reduce or eliminate human exposure to classroom noise and environmental noise pollution.” The report also urges the secretary to consider the American National Standards Institute (ANSI)-approved Standard S12.60-2002 [Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools] in providing technical assistance to schools. “This bill is an important step to help make our schools safer, greener, and better learning environments for our children,” McCarthy said. “Children cannot learn and teachers cannot teach in crumbling, noisy schools where poor physical conditions distract from classroom activities.” ASHA President Sue Hale commended McCarthy’s efforts, saying that “ASHA applauds Rep. McCarthy’s commitment to ensure that children have an appropriate environment in which to learn. Reducing classroom noise and ensuring appropriate acoustics are essential elements to all children’s academic success.” Hill Briefing In May ASHA hosted a Capitol Hill briefing attended by more than 50 individuals, including congressional staff, federal agency representatives, organizations representing individuals with hearing impairment, and ASHA audiologists who were conducting a “Hill Day” advocacy event. The briefing, “Classroom Noise and Acoustics: The Unseen Barriers to Learning,” was moderated by Arlene Pietranton, ASHA executive director. Panelists included Illinois 12-year-old Nicole Hubert, who has bilateral cochlear implants; ASHA member Peggy Nelson, professor of audiology at the University of Minnesota; architect Marcus Adrian; Kenneth Roy, chief acoustician for Armstrong World Industries (manufacturer of acoustic tiles); and Elizabeth Stewart from the United States Access Board, an independent federal agency that ensures access to federally funded facilities and a leading source of information on accessible design. Panelists said that reducing noise and improving acoustics encourages academic progress, does not have to be expensive, and is in practice all over the country. Author Notes Neil Snyder, director of federal advocacy, can be reached at [email protected] or 800-498-2071, ext. 5614. Advertising Disclaimer | Advertise With Us Advertising Disclaimer | Advertise With Us Additional Resources FiguresSourcesRelatedDetails Volume 14Issue 9July 2009 Get Permissions Add to your Mendeley library History Published in print: Jul 1, 2009 Metrics Downloaded 66 times Topicsasha-topicsleader_do_tagleader-topicsasha-article-typesCopyright & Permissions© 2009 American Speech-Language-Hearing AssociationLoading ...

Integrating acoustical issues in the design of high-performance schools.

ANSI 12.60 presents acoustical performance criteria for interior finishes to control reverberation inside classrooms, provide sound isolating wall and floor/ceiling assemblies between rooms, and limit noise from building equipment to allow perception and understanding of human voices within educational occupancies by young listeners with normal hearing and some degrees of hearing impairments. In practice, many schools are built that develop in an uneasy way trying to meet or sometimes to avoid meeting ANSI criteria because of perceived difficulties and expense in achieving the required results. A method to integrate acoustical design principles with the basic architectural design scheme of a school that can be implemented early in the design process was developed so acoustical performance can be simply implemented in school projects. This paper presents a core set of acoustical planning principles that can be implemented early in the design process so that ANSI criteria for room finishes, sound isolation,...

Leadership in Energy and Environmental Design for schools: Unintended consequences? Going “green” and the implications on classroom acoustics.

The advent of the LEED for Schools Minimum Acoustical Performance criteria is a welcome step in the development of green building design. Recent experiences with trying to meet these criteria have led to frustration on the part of architects and the subsequent relaxation of the criteria by the USGBC into a more attainable structure. While the movement to incorporate green design is imperative, the relaxed acoustic criteria may actually be counterproductive in achieving a reasonable acoustic environment for learning. Has good acoustic practice been sacrificed for the green label and is it worth it? A recent case study will be presented.

Students and Soundwaves: Five Strategies to Promote Good Classroom Acoustics

Students and Soundwaves: Five Strategies to Promote Good Classroom Acoustics

Understanding Intervention for (C)APD: As Easy as A-B-C

Understanding Intervention for (C)APD: As Easy as A-B-C