Reverberation time

BACKGROUND

Reverberation time, or RT60, is a metric which describes the length of time taken for a sound to decay by 60 dB from its original level. Optimal reverberation times vary depending on room volume, intended use of the space and the frequency of transmitted sound. In spaces with high reverberation times, the sounds of voices and footsteps take longer to dissipate, contributing to higher levels of ambient noise. The noise produced by reverberation can decrease speech intelligibility and in some situations cause additional stress. This performance specification can be met through the use of sound-absorbing materials on various surface and design elements.

Endocrine

Cardiovascular

Nervous

Part 1
Reverberation Time

VERIFICATION

The following spaces have maximum reverberation time (RT60) as described:

a.⁹⁰

Conference rooms: 0.6 seconds.

Open workspaces: 0.5 seconds.

On Site
Performance Test

Part 2
Reverberation Time for Learning Spaces

VERIFICATION

Reverberation time measurements for learning spaces meet the following criteria:

a.¹³³

Spaces less than or equal to 280 m³ [10,000 ft³]: less than 0.6 seconds.

b.¹³³

Spaces greater than 280 m³ [10,000 ft³] and equal to or less than 570 m³ [20,000 ft³] : less than 0.7 seconds.

On Site
Performance Test

	Core & Shell	New & Existing Buildings	New & Existing Interiors
Part 1: Reverberation Time	-	O	O

	Commercial Kitchen	Education	Multifamily Residential	Restaurant	Retail
Part 2: Reverberation Time for Learning Spaces	-	O	-	-	-

Verification Methods Matrix

	Letters of Assurance	Annotated Documents	On-Site Assessment
Part 1: Reverberation Time			Performance Test
Part 2: Reverberation Time for Learning Spaces			Performance Test

Standard Citations

90

U.S. General Services Administration Center for Workplace Strategy Public Buildings Service. Sound Matters: How to Achieve Acoustic Comfort in the Contemporary Office. Washington, D.C.: 2012: 11, 29, 32, 33, 36.
78.1.a	The General Services Administration's Sound Matters recommends RT60 of 0.6 seconds for meeting rooms.

**133**

Accredited Standards Committee, S12 Noise. ANSI/ASA S12.60-2010/Part 1 American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 1: Permanent Schools. Melville, NY: Acoustical Society of America; 2010:8-10.
78.2.b	ANSI/ASA S12.60-2010 Part 1 recommends maximum permitted reverberation times for core learning spaces greater than 10,000 ft³ and equal to or less than 20,000 ft³ to be 0.7 seconds.
78.2.a	ANSI/ASA S12.60-2010 Part 1 recommends maximum permitted reverberation times for core learning spaces of less than or equal to 10,000 ft³ to be 0.6 seconds.