IEC 60645-1:2017

Overview

IEC 60645-1:2017 - "Electroacoustics - Audiometric equipment - Part 1: Equipment for pure‑tone and speech audiometry" is an international standard that specifies general technical and performance requirements for audiometers used to determine hearing thresholds and to perform psychoacoustic tests with speech material. The fourth edition (2017) consolidates requirements for both pure‑tone audiometry and speech audiometry into a single document to eliminate contradictions between prior separate parts.

The standard’s objective is to ensure:

• consistency of hearing threshold results between compliant audiometers (125 Hz to 16 kHz),
• valid comparison to reference thresholds of hearing,
• standardized presentation of speech materials,
• classification of audiometers by signal range, operation mode, or primary application.

Key topics and technical requirements

IEC 60645-1 covers technical requirements across the full audiometric workflow, including:

• Test signals: specifications for pure tones and speech signals (frequency range 125 Hz–16 kHz), frequency accuracy, frequency modulation, and total harmonic distortion limits.
• Speech audiometry: standardized speech signal presentation, calibration signals, live‑voice microphone response, and free‑field/loudspeaker output level requirements.
• Transducers: requirements for earphones (supra‑aural, circumaural, insert), loudspeakers and bone vibrators, and headband force considerations.
• Masking sounds: narrow‑band and speech‑weighted masking noise characteristics and level controls.
• Signal level control and accuracy: marking, level indicator requirements, hearing level control accuracy, and masking level accuracy.
• Acoustic and electrical safety: acoustic safety limits, electromagnetic compatibility (EMC), environmental conditions, power supply variation, and unwanted sound controls.
• Calibration and test procedures: calibration signals, electrical output specification, test requirements to demonstrate conformity, and maximum permitted measurement uncertainty.
• Documentation and marking: required marking, instruction manuals, and audiogram format.

Practical applications and users

IEC 60645-1 is essential for:

• Audiometer manufacturers - to design, verify and certify devices that meet international performance and safety criteria.
• Clinical audiologists and hearing clinics - to select compliant audiometric equipment and ensure reproducible patient results.
• Calibration and test laboratories - for conformity testing, calibration procedures and uncertainty evaluation.
• Regulatory bodies and procurement teams - to specify technical requirements in tenders and standards compliance checks.

Adherence improves comparability of hearing tests across devices and settings, supports accurate audiograms, and ensures standardized speech testing.

Related standards

• This edition cancels and replaces the previous IEC 60645‑1 (third edition, 2012) and IEC 60645‑2 (1993), combining their requirements into a single, technically revised document.