Overview
ISO 23351-2:2026 – Acoustics - Measurement of Speech Level Reduction of Furniture Ensembles and Enclosures - Part 2: Field Method – is an international standard developed by ISO to provide a reliable field method for determining the apparent speech level reduction of furniture ensembles and enclosures. This standard specifies acoustic measurement procedures outside laboratory settings, meeting an engineering grade of accuracy. It is applicable for testing complete furniture ensembles and enclosures, typically used by one or more occupants, such as pods, meeting booths, or multi-component workstations. The approach ensures that products' acoustic performance can be evaluated in situ, where installation and operation conditions reflect real-world environments.
Key Topics
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Scope of Application
- The standard focuses on full furniture ensembles or enclosures, not on individual workstation components (e.g., screens, tables, chairs).
- Applicable to test objects assembled in finished rooms and intended for use by one or more occupants.
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Measurement Method
- Apparent speech level reduction is determined by comparing sound power levels with and without the test object in the chosen environment.
- Measurements are performed using sound sources that simulate normal speech and high-precision microphones placed in defined positions.
- Procedures accommodate both fixed microphone positions and scanning methods, adapting to the size and configuration of the test object.
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Field Testing Conditions
- The room used for measurement must provide adequate space around the test object and meet specified requirements for wall and ceiling proximity.
- Environmental and background noise corrections are applied as per ISO 3744 and ISO 3382-2 standards.
- The test object is positioned according to the manufacturer’s instructions and is unoccupied during testing to ensure consistency.
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Reporting and Data
- Results include detailed specifications of the test object, test environment, equipment used, measurement conditions, and outcomes.
- Recommendations ensure that manufacturer claims about acoustic performance can be verified reliably.
Applications
Related Standards
- ISO 23351-1: Laboratory method for measuring speech level reduction in smaller test objects under controlled conditions.
- ISO 3744: Engineering methods for determination of sound power levels and sound energy levels using sound pressure.
- ISO 3382-2: Measurement of room acoustic parameters, including reverberation time in ordinary rooms.
- IEC 60942: Specifications for sound calibrators used in acoustic measurements.
- IEC 61260-1 & IEC 61672-1: Specifications for electroacoustic measurement equipment, including sound level meters and filters.
ISO 23351-2:2026 ensures consistent, accurate, and comparable assessments of speech level reduction by furniture ensembles and enclosures in diverse real-world environments. By following this international standard for acoustic measurement in field settings, organizations can better evaluate, select, and verify privacy-enhancing furniture solutions for modern workplaces and public interiors.
