DIN 45681 establishes methods for detecting and assessing the tonal audibility of noise immissions, which is essential for determining noise annoyance potential and regulatory compliance. Tonal noise components (pure tones or narrow-band frequencies) are perceived as more annoying than broadband noise at equivalent sound pressure levels, making tonality assessment critical for environmental noise evaluation. The standard defines objective procedures to quantify tonality and adjust noise exposure assessments accordingly. Accreditation for this test method enables laboratories to conduct accurate environmental noise impact assessments, particularly for industrial operations, mechanical systems, and wind energy projects where tonal characteristics significantly influence regulatory requirements and resident protection.
What it measures
Presence and audibility of tonal components in noise
Frequency and sound pressure level of pure tones
Prominence of tonal components relative to background noise
Tonality-adjusted noise rating and regulatory impact
Narrow-band spectral analysis and tone identification
Environmental noise assessment and regulationRenewable energy and wind turbine developmentIndustrial operations and manufacturingHVAC and building systems acousticsTransportation and infrastructure noise control
Related Standards
DIN 45680Low-frequency noise measurement and assessment
ISO 1996-1Acoustics — Description, measurement and assessment of environmental noise — Part 1: Basic quantities and assessment procedures
DIN 45645-2Beurteilung von Musikdarbietungen durch ihre Umgebung — Teil 2: Meßtechnik und Beurteilung
Scope