Overview
EN ISO 354:2003 - Acoustics: Measurement of sound absorption in a reverberation room (ISO 354:2003) specifies a standardized method for measuring the sound absorption coefficient of acoustic materials (wall/ceiling treatments) or the equivalent sound absorption area of objects (furniture, people, space absorbers) using a reverberation room. Results are intended for comparison, product characterization and for use in room acoustics and noise control design calculations. The standard is not intended for measuring weakly damped resonators.
Key topics and technical requirements
- Measurement principle: Determine average reverberation time (T) in a reverberation room with and without the test specimen and compute the specimen’s equivalent absorption using Sabine’s equation.
- Sound field requirements: Tests assume a diffuse sound field approximated in a properly designed reverberation room (see Annex A).
- Measurement methods:
- Interrupted noise method (direct decay recording)
- Integrated impulse response method (reverse-time integration of impulse responses)
- Frequency range: Measurements in one‑third‑octave bands with centre frequencies from 100 Hz to 5 000 Hz (ISO 266 preferred frequencies).
- Terms and results: Defines decay curves, reverberation time (T), equivalent sound absorption area (A) and sound absorption coefficient (αs). Note: αs from reverberation measurements can exceed 1.0 (diffraction effects).
- Test arrangement and specimen mounting: Requirements for reverberation room layout, diffusion of sound field and defined specimen mounting types (including updates from previous edition such as Type B and Type J).
- Environmental and procedural controls: Specifies temperature/relative-humidity considerations and measurement precision (see sections on measurement of reverberation time, precision and presentation of results).
- Reporting: Prescribed content for a standardized test report.
Applications and who uses it
- Acoustic test laboratories performing standardized absorption measurements.
- Manufacturers of acoustic panels, ceiling tiles, room absorbers and furniture seeking product performance data.
- Acoustic consultants, architects and building designers using absorption data for room acoustics design, speech intelligibility, HVAC noise control and interior acoustic treatment calculations.
- Researchers comparing materials or validating modelling approaches.
Practical uses include performance comparison of absorptive treatments, specifying materials for auditoria/office spaces, and generating input data for acoustic simulation and noise-control calculations.
Related standards
- ISO 266 - Preferred frequencies (used for octave/third-octave band centres)
- ISO 9613-1 - Attenuation of sound outdoors (atmospheric absorption)
- IEC 61260 - Octave-band and fractional-octave-band filters
Keywords: EN ISO 354:2003, sound absorption, reverberation room, reverberation time, sound absorption coefficient, room acoustics, acoustic measurements, noise control.