Overview
IEC TS 61400-11-2:2024 is a Technical Specification from the IEC that defines measurement procedures to determine wind turbine sound characteristics at receptor (immission) positions. It focuses on sound immission assessment at far‑field locations (receptors) for single turbines and wind farms, and provides methodologies tailored to wind energy rather than typical industrial noise sources. The document promotes consistent, accurate description of turbine noise for environmental assessment, compliance and research.
Key topics and technical requirements
The standard covers measurement planning, instrumentation, data handling and reporting for receptor‑position noise assessment. Major technical topics include:
- Outline of method and test planning (representative conditions, site effects)
- Instrumentation: acoustic instruments (A‑weighted levels, 1/3‑octave and narrowband spectra), calibrators, audio recording, and non‑acoustic sensors (anemometry, meteorological, GNSS)
- Measurement setup: receptor and proxy locations, mounting and time synchronization
- Non‑acoustic measurements: wind speed binning, wind direction, precipitation and environmental parameters
- Data reduction and uncertainty: bin analysis, averaging methods, uncertainty estimation
- Sound metrics: equivalent continuous A‑weighted levels (LAeq), statistical levels (LAx), and sound power level based regulatory schemes
- Specific phenomena: tonal audibility (ISO/TS 20065 referenced), amplitude modulation, impulsivity, low‑frequency sound and infrasound guidance
- Prediction and propagation: references to ISO 9613‑2, Nord2000 for sound propagation and regulatory approaches
- Reporting: comprehensive reporting requirements including instrumentation, environment, turbine characterization and uncertainty
Applications and who uses it
IEC TS 61400-11-2:2024 is intended for professionals involved in wind turbine noise measurement and assessment:
- Acoustical consultants and test laboratories performing receptor noise surveys and post‑construction verification
- Wind farm developers and operators assessing operational noise and community impact
- Regulators and permitting authorities using standardized measurement methods for compliance checks
- Environmental impact assessors integrating receptor noise data into EIA studies
- Researchers studying tonal audibility, amplitude modulation and low‑frequency effects
Practical uses include compliance testing, community noise assessments, design validation, mitigation planning and scientific studies of turbine sound characteristics.
Related standards
- IEC 61400 series (wind energy generation systems)
- ISO/TS 20065 (tonal audibility method) - referenced
- ISO 9613‑2 and Nord2000 (sound propagation/prediction) - referenced
Keywords: IEC TS 61400-11-2:2024, wind turbine sound characteristics, receptor position, acoustic noise measurement techniques, wind farm noise, tonal audibility, amplitude modulation, noise assessment, sound immission.