Newmat aia presentation

Architectural Applications for Stretched Membrane Acoustic

Systems

NEWMAT is a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for AIA members are available on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing with any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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Newmat USA 2013

Learning Objectives

• To understand the major aspects of architectural acoustics.

• To identify the health effects of poor acoustics.

• To review the benefits and performance of stretched membrane acoustic systems.

• To discover how stretched membrane systems apply to a variety of project types.

Introduction

Major Aspects of Acoustics

Quality of Sound in a Room/Space

• Reverberation Time (RT60)

• The amount of time a direct sound takes to decay 60 dB

• Controlled by implementing absorptive materials

• Frequency Response

• Depending on the acoustic characteristics of a room, some frequencies will take longer to decay than others.

• Various materials absorb more effectively at different frequencies.

• Echoes

• Caused by distinct reflections reaching the listener with a time delay from the direct sound.

• Diffusion is used to control distinct echoes without removing sound energy from a space.

• Speech intelligibility can be negatively affected by excess reverberation (>0.5s), which can be a potential life safety issue when critical instructions need to be heard and understood.

Quality of Sound in a Room/Space

Did you Know?

• Because vowels are louder and lower in frequency (a more reverberant sound in typical spaces) than consonants, they can mask consonant information and lower speech intelligibility.

Containment of Sound Between Spaces

• Isolation of sound between spaces depends on three factors:

• Mass

• Airspace

• Resilient Connections

• Isolating sound within a space and acoustically treating a space are approached separately in the design process.

• Acoustic treatments (absorption/diffusion) do not significantly affect a space’s isolation. Likewise, isolated spaces do not necessarily have desirable acoustical properties within them.

Containment of Sound Between Spaces

Did you Know?

According to a monthly report published by Los Angeles World Airports (LAX, LAWA, ONT, VNY), there were 324 reported noise complaints in August of 2013. That is a great reason to implement isolation techniques in hotel, residential, and commercial applications to keep all of your clients happy!

Control of Noise Generated Within Spaces

• Noise is defined as any unwanted sound that gets in the way of what a listener wants to hear.

• Noise can originate from outside a building, HVAC systems, adjacent interior spaces, and other equipment within the space such as computers and appliances.

• Minimizing penetrations for mechanical systems is important to maintain a reasonable level of isolation between spaces.

• It is also important to resiliently support mechanical equipment including spring mounts and neoprene isolators.

Control of Noise Generated Within Spaces

Did you Know?• According to a study published in the American Journal of

Audiology, many classrooms do not meet preferred acoustic standards concerning noise.

• The signal to noise ratio (e.g., teacher’s voice to background noise) should be +15dB at the students’ ears for good intelligibility.

• Noise levels in an unoccupied classroom should not exceed 35dBA to ensure that all students can learn effectively.

Health Effects of Bad Acoustics

According to the World Health Organization, noise can cause: hearing impairment, hypertension, heart disease, annoyance and tinnitus - a constantly perceived ringing or hissing, even when no external sound is present.

An estimated 10 million people in the U.S. have noise-related hearing loss.

Acoustics in the Workplace

Twenty-two million workers are exposed to potentially damaging noise each year. In 2007, approximately 82% of the cases involving occupational hearing loss were reported among workers in the manufacturing sector.

According to the National Institute for Occupational Safety and Health, an estimated $242 million is spent annually on worker’s compensation for hearing loss.

Noise has been shown to increase workplace accident rates.

Acoustics in the Classroom

Noise is distracting and has been linked to poor school performance.

In a study conducted by Cornell University, children exposed to noise in learning environments experienced trouble with word discrimination and suffered from various cognitive developmental delays.

Teachers’ vocal health is also a concern when they have to strain to be understood.

Acoustics in the Home

Do you enjoy the sound of crickets chirping at night to help you sleep? Does the sound of a busy city outside your window bother you? What may be a pleasant sound to your neighbor may not be a pleasant sound to you.

Noise has been linked to sleep disturbance, changes in the immune system, and even birth defects.

Children from noisy residences often possess a heart rate that is significantly higher (by 2 beats/min on average) than that of children from quieter residences.

Acoustics in Social LifeNoise can cause stress and stimulate aggression and other anti-social behaviors. This can result in an increased risk of depression, psychological disorders, migraines, and even emotional stress.

Results from Improvements in Acoustics Within an Environment

• The ability of office workers to focus on their tasks improved by 48%.

• “Conversational distractions” decreased by 51%.

• Error rates: Performance of tasks improved 10%.

• Stress was reduced by approximately 27%.

Stretched-Membrane Acoustic Systems

General Benefits

• Easily installed in new and existing spaces

• Meets all applicable fire codes• Easily cleanable and

maintainable• High accessibility factor• Flexible design configurations• Wide range of aesthetic options• Ability to tailor acoustic

performance

General Theory

How does a stretched membrane work for sound

absorption?

Non-Perforated

Perforated Applications

• Non-Perforated• Perforated

• Standard Perforations• Micro-Perforations

Non-Perforated Membrane

• Non-perforated membranes absorb primarily mid to low frequencies because of their diaphragmatic action, which converts acoustical energy to heat.

• When low frequency sound hits a solid acoustic membrane, instead of reflecting off the membrane and contributing to the total sound energy in the room, the energy instead causes the membrane itself to resonate.

Perforated Membrane• Perforated membranes allow more high frequency

information through, which is attenuated in the cavity with backing materials. At the same time, more energy is reflected than if the backing material were fully exposed, which avoids creating a “dead” sounding space.

• Perforated membranes act as a Helmholtz resonator which effectively tunes the absorption, based on the dimensions of the perforations and the cavity depth.

Micro-Perforated Membrane

• Micro-perforations allow for the same benefits as standard perforations while maintaining a uniform and smooth appearance, even at low ceiling heights.

• Micro-perforations (cone shaped):• Broaden the bandwidth of absorption• Raise the frequency of peak absorption• Increase absorption at mid to high frequencies• Function similarly to commonly used acoustical wood

products with shaped slots

Micro-Perforated Membrane

Effects of Backing Acoustic Cores

• Insulation – Increases total absorption of the system based on the thickness and density of the material. The following are most effective at:

• 4”, 3lb/ft3 – 250Hz and above• 2”, 3lb/ft3 – 500Hz and above• 1”, 3lb/ft3 – 1KHz and above

• The use of two membranes also increases absorption, primarily in the mid frequencies.

• An air gap increases absorption, even in systems already using insulation material.

• The air gap between membranes may be used to fine tune the frequencies of peak absorption.

Acoustic Transparency

• Loudspeakers may be concealed behind material that is sufficiently transparent.

• Transparent materials are also used for sound diffusion and other non-absorptive applications.

Comparison of Lab Tests

One vs. Two Layers of Newmat with Micro-Perforated Membrane

Variable Cavity Insulation Conditions

Variable Airspace Behind Membrane

Solid vs. Standard vs. Micro-Perforations

Sound Transmission Loss

Applications and Case Studies

ResidentialNeeds and benefits for home applications

1. Preventing excessive audio build-up in media spaces.

2. Calming bedroom and other relaxation environments.

3. Preventing noises generated in kitchens and other work spaces from spreading to other areas of the home.

Residential – Examples and Case Study

Living Rooms, Home Theaters, Kitchen/Bath, Home Gyms, Etc.

Private Loft, Minneapolis, MNNon-perforated suede membrane over 1” fiberglass NRC .70

Workplace Needs and benefits for workplace applications

1. Improving conversational intelligibility in private offices and conference rooms.

2. Enhancing speech privacy in open plan office areas.

3. Controlling loudness in excessively noisy work environments.

Private Offices, Open-plan Areas, Conference Rooms, Boardrooms, Etc.

Workplace

Bank of America Headquarters, Charlotte, NC2 layers of micro-perforated membrane over air cavity

and 1” fiberglass NRC .75

Dining/Clubs

Needs and benefits for Dining/Club applications

1. Controlling volume and distortion level of music.

2. Increasing the ability to understand other people talking without the need to shout.

3. Reduce miscommunication between customers and waiters when taking orders.

Dining/Clubs – Examples and Case Study

Restaurants, Bars, Nightclubs, Other Small Scale Venues, Etc.

The Wright at the Guggenheim Museum, New York, NY

Non-perforated membrane over air cavity NRC .40

Arts/Cultural

Needs and benefits for

Arts & Cultural applications

1. Optimizing acoustic performance for live music or speech events.

2. Enhancing the intelligibility and clarity of multi-media programs.

3. Reducing ambient noise level from public crowds.

Arts/Cultural – Examples and Case Study

Performance Halls, Museums, Rehearsal Spaces, Recording Studios, Etc.

Chanhassen High School, Chanhassen, MNMicro-perforated suede membrane over air cavity and cellulose spray

NRC .85

Houses of Worship

Needs and benefits for HOW applications

1. Ensuring maximum intelligibility of the spoken word.

2. Creating the ideal environment for contemplation and prayer.

3. Reducing the impact of stray sounds from the congregation (e.g., babies crying) during the service.

Houses of Worship – Examples and Case Study

Churches, Synagogues, Temples, Fellowship Halls, Etc.

St. Thomas Church, West Hempstead, NYMicro-perforated membrane over ACT NRC .65

Sports/Recreation

Needs and benefits for

Sports & Recreation applications

1. Taming the sound level of extremely loud crowds.

2. Improving on-court communication with players.

3. Reducing stress levels by preventing exposure to a highly reverberant space.

Sports/Recreation – Examples and Case Study

Arenas, Indoor Pools, Gymnasiums, Indoor Tennis Courts

Sherwood Gymnasium, Sherwood, ORMini-perforated membrane over 6” Batt insulation NRC .90

Additional Applications

College of Education, San Bernardino, CAMicro-perforated membrane over air cavity

and 2”-3 pcf insulation NRC .90

Additional Applications

Fayetteville Public Library, Fayetteville, ARMicro-perforated membrane over air cavity and steel deck

NRC .50

Additional Applications

Grand Hyatt Hotel Lobby, New York, NYNon-perforated membrane over air cavity NRC .35

Additional Applications

James Turrell Exhibit at the Guggenheim, New York, NY2 layers of micro-perforated membranes over air cavity NRC .55

Additional Applications

Logan, New York, NY2 layers of non-perforated membrane over air cavity NRC .45

Additional Applications

Museum of Fine Art, Boston, MA2 layers of micro-perforated membrane over air cavity NRC .50

Additional Applications

NYU Natatorium, New York, NYNon-perforated membrane over air cavity and cellulose spray NRC .55

Additional Applications

Providence Public Safety Complex, Providence, RIMicro-perforated membrane over air cavity and 6” Batt insulation NRC .85

Additional Applications

St. Louis Zoo, St. Louis MOMicro-perforated membrane over air cavity NRC .50

Additional Applications

The Modern at MOMA, New York, NYNon-perforated membrane over air cavity and 4” Batt insulation NRC .65

Additional Applications

Themed Residential Environment – Irvine, CAMicro-perforated suede membrane over air cavity and 6” Batt insulation

NRC .90Four custom sound radiating speaker panels were installed

directly above the membrane and provide excellent transmission of audio through the membrane with digital signal processing.

Additional Applications

Washington Dulles International Airport, Chantilly, VA2 layers of micro-perforated membrane over air cavity

and 2” acoustical boards

NRC .75

Additional Applications

WGBH Boston, MAMicro-perforated membrane over air space and 2” cellulose spray NRC .85

Architectural Applications for Stretched Membrane Acoustic

Systems

This concludes the AIA portion of this presentation. Thank you for your time,

and for more information, please visit NewmatUSA.com