Overview
EN ISO 11688-1:2009 (ISO/TR 11688-1:1995) - “Acoustics - Recommended practice for the design of low-noise machinery and equipment - Part 1: Planning” is a technical report adopted by CEN to help designers incorporate noise control from the earliest project phases. It explains basic acoustical concepts and presents a methodical design process to reduce noise emissions in machinery and equipment. The document supports conformity with EU machinery directives (see informative Annexes ZA and ZB) and cross-references established ISO measurement and declaration methods.
Key topics and requirements
- Design process for low-noise machinery: Describes four iterative phases - clarification of task (requirements), conceptual design, detailed design, and prototyping/final testing - with acoustical checkpoints at each stage.
- Noise source classification: Differentiates active components (noise generators) from passive components (structural radiators) and distinguishes tonal, periodic and broadband noise.
- Design rules and controls: Summarized guidance (Annex A) and noise control requirements (Annex B) for selecting materials, dimensions, and concepts that minimize airborne, structure-borne and fluid-borne noise.
- Measurement and verification: Recommends use of established ISO methods for quantifying noise and source strengths; references include ISO 3744, ISO 3746, ISO 4871, ISO 9611, ISO 9614-1/-2, ISO 11200 and ISO 11689.
- Documentation and reporting: Annex C lists information to be reported; Annex D provides a bibliography of acoustical literature for further study.
- Practical scope: Serves as an aid to non-acoustic engineers and design teams to assess, compare and implement noise reduction measures during product development.
Practical applications
- Integrating noise control into early product planning and requirement specification.
- Comparing alternative machine concepts by predicted noise performance (design trade-offs).
- Guiding prototype testing and acoustical diagnosis to target the most effective noise mitigation measures.
- Supporting compliance evidence for noise emission requirements and EU machinery directives.
- Informing purchasing/specification decisions where low-noise performance is a competitive or regulatory requirement.
Who should use this standard
- Mechanical and product designers wanting to minimize machine noise
- Acoustical engineers and test laboratories performing prototype measurements
- Compliance officers and technical managers preparing machinery for EU markets
- R&D teams applying noise-reduction best practices in concept development
Related standards
EN ISO 11688-1:2009 is a planning-focused guide that connects acoustical theory and measurement practice to actionable design decisions for quieter machinery. Keywords: acoustics, low-noise machinery, noise control, machine design, ISO 11688-1, noise measurement, sound power, noise emission.