ISO 362-1:2022

Overview

ISO 362-1:2022 - Acoustics: Engineering method for measurement of noise emitted by accelerating road vehicles - Part 1: M and N categories - defines a repeatable, engineering-focused test method to measure the noise emitted by road vehicles of categories M (passenger transport) and N (goods transport) under typical urban traffic conditions. The standard is designed for simplicity and reproducibility and is intended for controlled test environments (extensive open space) used in type approval, manufacturing checks, and official test stations. It provides objective sound pressure measurements while noting that subjective human annoyance is outside its scope.

Key topics and technical requirements

• Scope and vehicle coverage: Applies to vehicle categories M and N; excludes two‑ and three‑wheelers (L1–L5) - see ISO 9645 and ISO 362‑2 for those categories.
• Test philosophy: Reproduces principal noise sources during normal urban driving by combining a wide‑open‑throttle acceleration phase and a constant‑speed phase to simulate in‑use urban conditions.
• Acceleration specification and calculation: Procedures to calculate target and reference accelerations, with different methods for manual, automatic, adaptive and CVT transmissions and treatments for locked vs non‑locked gear ratios.
• Instrumentation: Requirements for acoustical measurement systems (microphones, calibration, data acquisition), speed and meteorological instrumentation, and conformity checks.
• Acoustical environment and meteorology: Tests require a large open test site, defined meteorological conditions, and limits on background noise to ensure valid measurements.
• Microphone positions and operating conditions: Defined microphone locations, vehicle preparation (test mass, tyre selection, battery state), additional sound‑emitting devices, and cooling system controls.
• Data handling and uncertainty: Procedures for measurement readings, data compilation, reported values, and a framework for measurement uncertainty (reference to ISO/IEC Guide 98‑3).
• Annexes and tools: Informative annexes provide technical background, uncertainty analysis, and flowcharts for different vehicle categories and test modes.

Practical applications and users

• Vehicle manufacturers for type‑approval testing and production quality checks.
• Certification bodies and regulatory agencies conducting official noise compliance testing.
• Acoustic test laboratories and test stations implementing standardized vehicle noise measurement procedures.
• OEM calibration and R&D teams evaluating vehicle noise sources and mitigation measures.
• Environmental and urban planners using objective data for noise mapping and policy development.

Related standards

• ISO 9645 - two‑ and three‑wheel vehicles (L1, L2)
• ISO 362‑2 - other L categories (L3, L4, L5)
• ISO/IEC Guide 98‑3 - measurement uncertainty framework referenced in annexes

ISO 362-1:2022 is a practical, internationally recognized method for consistent measurement of accelerating vehicle noise in urban contexts, supporting regulatory compliance, product development, and objective acoustic assessment.