Overview
ISO 11689:1996 - Acoustics: Procedure for the comparison of noise‑emission data for machinery and equipment defines a standardized method to compare noise‑emission data so users can determine noise‑control performance for a family, type or group of machines. The standard describes how to collect, present and evaluate measured noise quantities (e.g., A‑weighted sound power LWA, A‑weighted emission sound pressure LpA, C‑weighted peak Lpc,peak) and how to derive statistical lines (L‑lines) and regression analyses to rank machines by noise performance.
Key topics and technical requirements
- Scope and applicability: Applies to any machinery or equipment with comparable noise‑emission data or an established noise test code; in principle adaptable to other physical agents (e.g., vibration).
- Machine classification: Machines must be classified into families, groups and sub‑groups so each machine maps unambiguously to one group for comparison.
- Noise‑emission quantities: Principal quantities (LWA, LpA, Lpc,peak), additional quantities (surface emission levels, spectra, directivity, impulsiveness).
- Measurement methods: Use standardized noise test codes or basic acoustics standards (e.g., ISO 3740 series); document measurement method, grade of accuracy and operating conditions.
- Data representativeness: A data set is considered representative when coverage is adequate (recommendation: cover at least 50% of manufacturers and 50% of models sold in the group, or otherwise justify coverage).
- Presentation requirements: Values presented in tables and/or graphs (annex C form available); include regression line, L‑lines, dates, test code reference and machine characteristic parameters.
- Evaluation procedure: Use linear regression (annex A) and L‑lines (parallel to the regression line) to indicate cumulative frequency bands. Typical placement guidance: L1 at x = 70–95% and L2 at y = 10–30% cumulative frequency; L2 and L3 (if used) should be at least 3 dB apart to mark superior performance clusters.
- Reporting: Record identification data, measurement context, market coverage and optional anonymization rules.
Practical applications and users
ISO 11689 is useful to:
- Product designers and R&D teams benchmarking noise performance across a machine family.
- Procurement specialists and buyers comparing candidate machines by noise emission.
- Standards committees and test laboratories drafting noise test codes and safety standards.
- Regulators, occupational health authorities and consultants evaluating marketplace noise control trends.
- Manufacturers and database managers compiling machine noise‑emission databases.
Use cases include product comparison, setting procurement noise limits, documenting noise‑control improvements, and deriving indices of market‑level noise performance.
Related standards
Keywords: ISO 11689:1996, acoustics, noise emission, machinery, noise‑control performance, LWA, LpA, Lpc peak, L‑lines, noise test code, machine classification.