SIST EN ISO 389-1:2018 PDF

Overview

EN ISO 389-1:2018 (ISO 389-1:2017) - "Acoustics - Reference zero for the calibration of audiometric equipment - Part 1" defines the reference equivalent threshold sound pressure levels (RETSPLs) used as the reference zero for pure‑tone air‑conduction audiometers. The standard provides RETSPLs for supra‑aural earphones, expressed so they can be applied directly to audiometer calibration. RETSPLs are given for a generic class of supra‑aural earphones measured on an ear simulator complying with IEC 60318‑1, plus model‑specific tables (including IEC 60318‑3 acoustic coupler data) where available. Data in the standard are based on measurements from standardizing laboratories and published research; explanatory notes appear in Annexes A and B.

Key topics and requirements

• Scope and purpose: Establish a uniform reference zero for hearing threshold level measurements in pure‑tone air‑conduction audiometry worldwide.
• Reference data (RETSPLs): Median equivalent threshold sound pressure levels for otologically normal subjects (defined population is included in the standard).
• Measurement platforms:
  • Ear simulator: IEC 60318‑1 (preferred basis for generic RETSPLs).
  • Acoustic coupler: IEC 60318‑3 (model‑specific data tables may reference this).
• Model‑specific vs generic data: Use model‑specific RETSPLs when available for the exact earphone + simulator/coupler combination; otherwise apply the generic supra‑aural earphone dataset if the earphone meets the listed requirements (see clause 4.2).
• Normative references and definitions: Standard relies on IEC 60318‑1 and IEC 60318‑3 and defines terms such as ear simulator, acoustic coupler, RETSPL and hearing threshold.
• Guidance: Annex A (application of RETSPLs) and Annex B (notes on derivation) provide practical and interpretive guidance.

Applications and users

EN ISO 389-1:2018 is essential for:

• Calibration laboratories performing audiometer calibration and verification.
• Audiology clinics and hearing test centers ensuring consistent, traceable threshold measurements.
• Manufacturers of audiometers and earphones establishing device calibration states and technical specifications.
• Occupational health and safety services that perform hearing surveillance and comply with regulatory measurement consistency.
• Regulators and standards bodies referencing a uniform zero for hearing thresholds in standards and guidance.

Practical benefits include improved comparability of audiometric thresholds across devices, reliable occupational hearing monitoring, and standardized product testing.

Related standards

• IEC 60318‑1: Ear simulator for supra‑aural/circumaural earphones (normative for RETSPLs)
• IEC 60318‑3: Acoustic coupler for supra‑aural earphone calibration
• ISO 389 series (other parts covering inserts/circumaural earphones and high‑level guidance)
• ISO 7029 (relation of hearing thresholds to age)

Keywords: EN ISO 389-1:2018, ISO 389-1:2017, RETSPL, audiometer calibration, supra‑aural earphones, IEC 60318‑1, IEC 60318‑3, pure‑tone audiometry.