acoustic standards

This document lists the international standards for laboratory acoustics measurements, including ECMA standards, ISO standards, ASTM standards, and ANSI standards.

Sound Transmission Loss Measurement
The following standards utilize a pair of reverberation chambers, measurements of the space/time average sound pressure levels in each chamber and a measurement of the reverberation time in the receiving chamber to determine the ratio of the sound energy incident on a test element to the sound energy transmitted through the element.

• ASTM E90-99 Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements
• ISO 140- 1: 1997 Acoustics -- Measurement of sound insulation in buildings and of building elements -- Part 1: Requirements for laboratory test facilities with suppressed flanking transmission
• ISO 140- 2: 1991 Acoustics -- Measurement of sound insulation in buildings and of building elements -- Part 2: Determination, verification and application of precision data
• ISO 140- 3: 1995 Acoustics -- Measurement of sound insulation in buildings and of building elements -- Part 3: Laboratory measurements of airborne sound insulation of building elements

The following standard provides complimentary test information for determination of the sound transmission loss of a particular type of test element.

• ASTM E1408-91(1995)e1 Standard Test Method for Laboratory Measurement of the Sound Transmission Loss of Door Panels and Door Systems

The following standards utilize the sound transmission loss data obtained in accordance with the basic sound transmission loss measurement standard to determine a single number rating for the test element.

• ASTM E1332-90(1998) Standard Classification for Determination of Outdoor-Indoor Transmission Class
• ASTM E413-87(1999) Standard Classification for Rating Sound Insulation

Sound Absorption Measurement
The following standards utilize a reverberation chamber and a measurement of the reverberation time in the empty chamber and in the chamber containing the test element to determine the ratio of the sound energy incident on a test element to the sound energy absorbed by the element.

• C423-99a Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method
• ISO 354: 1985 Acoustics -- Measurement of sound absorption in a reverberation room

The following standard provides additional information for the mounting of specific types of test elements when measuring sound absorption using the ASTM C423 method.

• ASTM E795-93 Standard Practices for Mounting Test Specimens During Sound Absorption Tests

The following standards utilize a standing wave tube to determine the ratio of the sound energy normally incident on a test element to the sound energy absorbed by the test element. The normal acoustic impedance of the element may also be determined. The standing wave methods (ISO 10534-1 and ASTM C384) use a traveling microphone to measure the standing wave ratio using sound pressure level measurements in the tube. The transfer function methods (ISO 10534-2 and ASTM E1050) utilize two phase matched microphones and the cross spectrum between the microphones to determine the normal incidence acoustic impedance of the test element, from which the normal incidence sound absorption coefficient can be calculated.

• ISO 10534- 1: 1996 Acoustics -- Determination of sound absorption coefficient and impedance in impedance tubes -- Part 1: Method using standing wave ratio
• ISO 10534- 2: 1998 Acoustics - Determination of sound absorption coefficient and impedance in impedance tubes -- Part 2: Transfer-function method
• E1050-98 Standard Test Method for Impedance and Absorption of Acoustical Materials Using a Tube, Two Microphones, and a Digital Frequency Analysis System
• ASTM C384-98 Standard Test Method for Impedance and Absorption of Acoustical Materials by the Impedance Tube Method

Sound Power Level Measurement
The following standards utilize a reverberation chamber and measurements of sound pressure level to determine the sound power level emissions of the equipment under test. Each standard includes a direct method that requires measurement of the reverberation time in the chamber and a comparison method that is based on measurements of the sound pressure level emissions of a calibrated reference sound source. These sound power level measurement standards are utilized as underlying reference standards for various product test codes.

• ISO 3741: 1999 Acoustics -- Determination of sound power levels of noise sources using sound pressure -- Precision methods for reverberation rooms
• ANSI S12.31-1990 (R1996) Broad-Band Noise Sources in Reverberation Rooms, Precision Methods for the Determination of Sound Power Levels of
• ANSI S12.32-1990 (R1996) Discrete-Frequency and Narrow-Band Noise Sources in Reverberation Rooms, Precision Methods for the Determination of Sound Power Levels of

The following standards utilize an anechoic chamber, hemi-anechoic chamber or an essentially free field over reflecting plane test environment and measurements of sound pressure levels to determine the sound power level emissions of the equipment under test.

• ISO 3744: 1994 Acoustics -- Determination of sound power levels of noise sources using sound pressure -- Engineering method in an essentially free field over a reflecting plane
• ISO 3745: 1977 Acoustics -- Determination of sound power levels of noise sources -- Precision methods for anechoic and semi-anechoic rooms
• ANSI S12.35-1990 (R1996) - Sound Power Levels of Noise Sources in Anechoic and Hemi-Anechoic Rooms, Determination of
• ANSI S12.34-1988 (R1997) - Free-Field Conditions over a Reflecting Plane, Engineering Methods for the Determination of Sound Power Levels of Noise Sources for Essentially

The following standards provide additional requirements for the measurement of the sound power level emissions of reference sound sources made for the purpose of calibrating the reference sound source. Calibration measurement methods utilize direct measurement of sound pressure levels in either reverberant or anechoic test environments. Reverberant room methods require the measurement of the reverberation time in the chamber.

• ISO 6926: 1999 Acoustics -- Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels
• ISO 9614- 1: 1993 Acoustics -- Determination of sound power levels of noise sources using sound intensity -- Part 1: Measurement at discrete points
• ISO 9614- 2: 1996 Acoustics -- Determination of sound power levels of noise sources using sound intensity -- Part 2: Measurement by scanning
• ANSI S12.5-1990 (R1997) - Reference Sound Sources, Requirements for the Performance and Calibration of
• ANSI S12.12-1992 (R1997) Engineering Method for the Determination of Sound Power Levels of Noise Sources Using Sound Intensity
• ANSI S1.9-1996 Instruments for the Measurement of Sound Intensity

Sound Pressure Level Measurement
The following standard specify methods for measurement of sound pressure level emissions of equipment under test. These standards may be used as underlying reference standards for various product test codes.

• ANSI S1.13-1995 (R1999) Measurement of Sound Pressure Levels in Air
• ISO 11201: 1995 Acoustics -- Noise emitted by machinery and equipment -- Measurement of emission sound pressure levels at a work station and at other specified positions -- Engineering method in an essentially free field over a reflecting plane
• ISO 532: 1975 Acoustics -- Method for calculating loudness level

Product Test Codes
Product Test Code standards specify the methods to be utilized for the measurement of the noise emissions of a specific class of equipment. Most product test codes rely on basic underlying standards for the measurement of sound pressure and sound power levels. The test code specifies operational modes and test conditions specific to the class of equipment.

The following standards provide rules and guidelines for drafting product test codes and for utilizing the underlying sound pressure level and sound power level measurement standards in product test codes.

• ANSI S12.30-1990 (R1997) Sound Power Standards and the Preparation of Noise Test Codes, Guidelines for the Use of
• ISO 3740: 1980 Acoustics -- Determination of sound power levels of noise sources -- Guidelines for the use of basic standards and for the preparation of noise test codes
• ISO 12001: 1996 Acoustics -- Noise emitted by machinery and equipment -- Rules for the drafting and presentation of a noise test code
• ANSI S12.10-1985 (R1997) Methods for the Measurement and Designation of Noise Emitted by Computer and Business Equipment

The following are examples of test codes for various classes of equipment.

• ECMA-74 Measurement of Airborne Noise Emitted by Information Technology and Telecommunications Equipment, 6th edition (December 1999)
• ECMA-108 Measurement of High-Frequency Noise emitted by Information Technology and Telecommunications Equipment, 3rd edition (December 1996)
• ISO 7779: 1999 Acoustics -- Measurement of airborne noise emitted by information technology and telecommunications equipment
• ISO 9295: 1988 Acoustics -- Measurement of high- frequency noise emitted by computer and business equipment
• ISO 1680: 1999 Acoustics -- Test code for the measurement of airborne noise emitted by rotating electrical machines
• ISO 10302: 1996 Acoustics -- Method for the measurement of airborne noise emitted by small air- moving devices
• ISO 11094: 1991 Acoustics -- Test code for the measurement of airborne noise emitted by power lawn mowers, lawn tractors, lawn and garden tractors, professional mowers, and lawn and garden tractors with mowing attachments

Product Noise Declaration

• ECMA-109 Declared Noise Emission Values of Information Technology and Telecommunications Equipment, 4th edition (December 1996)
• ISO 9296: 1988 Acoustics -- Declared noise emission values of computer and business equipment
• ISO 7574- 1: 1985 Acoustics -- Statistical methods for determining and verifying stated noise emission values of machinery and equipment -- Part 1: General considerations and definitions
• ISO 7574- 2: 1985 Acoustics -- Statistical methods for determining and verifying stated noise emission values of machinery and equipment -- Part 2: Methods for stated values for individual machines
• ISO 7574- 3: 1985 Acoustics -- Statistical methods for determining and verifying stated noise emission values of machinery and equipment -- Part 3: Simple (transition) method for stated values for batches of machines
• ISO 7574- 4: 1985 Acoustics -- Statistical methods for determining and verifying stated noise emission values of machinery and equipment -- Part 4: Methods for stated values for batches of machines

A note about ECMA, ISO and ANSI test code standards and declaration standards for ITTE equipment – Many of the ITTE test codes are published by ECMA, ISO and ANSI. The current process is that new or revised standards are developed as a part of the ECMA process, as ECMA standards can be adopted quickly. The ECMA standards are then submitted to ISO for approval as an ISO standard and then submitted to ANSI for adoption as a consensus international standard. When the entire process is completed, the ECMA, ISO and ANSI standards become equivalent.



Additional References

Related NI Products:

• Sound and Vibration Toolset
  
  

Information Contributed By: David A. Nelson, P.E., INCE Bd. Cert. Nelson Acoustical Engineering, Inc. specializes in noise and vibration control, sound quality, laboratory facilities and test control systems, and instruction related to plants, buildings, laboratories, products, and machinery.

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Acoustic Standards
I need the acoustic standards for the environment of homes adjacent to a Rock Quarry. The noise is loud, distressing and effecting the value of our homes. I have discussed this with the Supervisor of quarries in this area. I would appreciate some guidance as to how we can determine if the noise level exceeds standards of businesses and people who live near by as well as the employees of the Quarry.
- Nov 6, 2007