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TC26

Acoustics

Upcoming meetings
  • DateNameLocation
  • 11 - 12 June 2025TC26 meeting – June 2025Stowe, USA

Items of interest and recent work

ECMA-74 specifies procedures for measuring and reporting the noise emission of information technology and telecommunications (ITT) equipment. The 20th edition of ECMA-74 contains revisions that refine printer categories and accommodate headless PCs.

Future revisions to ECMA-74 will address equipment whose noise changes with temperature, for example due to cooling loads, and broadened ambient temperatures and meteorological corrections.

ECMA-109 specifies how to declare noise emissions of ITT equipment. Instructions and examples for declaring sound pressure level at multiple operator positions and bystander positions will be added in the next 11th edition, and sound power level will be declared in dB (decibel) instead of the current declaration in B (bel).

ECMA-418 describes psychoacoustic metrics for ITT equipment and includes Part 1 (prominent discrete tones) and Part 2 (models based on human perception). The 2nd editions of ECMA-418-1 and ECMA-418-2 were published in December 2022 with improved definitions of terms, descriptions of procedures, and formulations of perceptual models. A  new fluctuation strength metric will be described in the 3rd edition.

Task Group TG1 focuses on measurement of noise, vibration, and tonality of small air-moving devices and is working on a measurement procedure that allows fan testing with optional application of airflow resistance (by the ISO 10302 plenum) and optional representation of nearby structures affecting airflow.

Task Group TG2 focuses on noise measurement of multi-function printers and related printing and imaging equipment and is working on a measurement procedure for slow printers that spend more than 30 seconds per page.

Task Group TG3 focuses on psychoacoustic metrics applicable to ITT equipment and is working on a fluctuation strength metric that describes the effect of time-varying sound intensity on perception.

Task Group TG4 focuses on noise measurement of rack-mounted equipment and is working on measurement procedures that address the various types of equipment, operating modes, and workloads of rack-mounted equipment, which is proliferating and moving into office spaces.

TC26 maintains liaison with ISO TC43/SC1/WG23 (IT noise) and ISO TC43/SC1/WG28 (Noise emission from all types of equipment). Through these liaisons, TC26 can influence ISO standards that affect IT product noise measurements.

Please find below 2 video clips made during the TC26 meeting in Portland (23-24 July 2011); the first one is an interview of Dr. Robert Lotz (past TC26 Chair) and the second one is an interview of Dr. E. K. Dunens (past TC26 Chair).