IEC 60318-1:2009

Overview

IEC 60318-1:2009 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies an ear simulator designed for the precise measurement of supra-aural and circumaural earphones. This standard focuses on electroacoustics and simulates the acoustical characteristics of the human ear to ensure accurate and repeatable measurement of earphone acoustic output.

The ear simulator described in IEC 60318-1 is applicable across a frequency range from 20 Hz up to 10 kHz and can be extended as an acoustic coupler up to 16 kHz. The standard is widely used in the fields of audiometry, telephonometry, and other applications requiring reliable earphone performance assessment.

This edition of the standard is a significant technical update from the 1998 version and introduces expanded measurement uncertainties, updated specifications for acoustic transfer impedance, and a method for measuring this impedance with defined tolerances.

Key Topics

• Ear Simulator Design:
  The device simulates the acoustic impedance of the human ear, tailored for two distinct earphone types:

  • Supra-aural earphones: fitted externally on the ear, resting on the pinna.
  • Circumaural earphones: enclose the entire ear, contacting surrounding head surfaces with cushions to avoid significant pinna compression.

• Measurement Range and Frequency Extension:
  Accurate measurements are guaranteed from 20 Hz to 10 kHz, with acoustic coupler capabilities up to 16 kHz for additional applications. High-frequency measurement repeatability above 10 kHz may show variability.

• Acoustic Transfer Impedance:
  The standard specifies exact acoustic transfer impedance requirements, including tolerances, to ensure the ear simulator accurately replicates human ear characteristics for reliable measurement results.

• Calibration and Measurement Uncertainty:
  The standard outlines calibration procedures under specified environmental conditions and expands on measurement uncertainty parameters to guide quality assurance in testing.

• Technical Construction Features:
  The ear simulator consists of three acoustically coupled cavities with a conical primary cavity housing a calibrated pressure-type microphone. The external coupling surface varies by earphone type to ensure optimal contact and prevent acoustic leakage:

  • Supra-aural earphone coupling features sloped sides matching ear cushion profiles.
  • Circumaural earphone coupling uses a flat surface compatible with a wide range of designs.

Applications

IEC 60318-1 ear simulators serve a critical role in industries and fields where precise acoustic evaluation of earphones is necessary:

• Audiometry:
  Enables accurate calibration and testing of supra-aural and circumaural earphones used in hearing tests and diagnostic equipment.

• Telephonometry:
  Assists in standardizing and measuring the output of communication headsets to ensure clarity and consistent audio quality.

• Product Development:
  Manufacturers use the standard to assess earphone acoustic performance during design and quality control phases.

• Regulatory Compliance:
  Helps organizations comply with international requirements for measuring and reporting earphone sound emissions.

Related Standards

• IEC 61094-4: Specifies standards for working standard microphones used in acoustic measurements, ensuring accuracy in microphones incorporated into the ear simulator.

• ISO/IEC Guide 98-3 (GUM): Provides guidelines for the expression of uncertainty in measurement, crucial for calibration procedures and quality assurance outlined in IEC 60318-1.

• Other IEC 60318 Series Parts:
  IEC 60318 is a multi-part series covering various simulators of human head and ear with each part tailored to different acoustic measurement scenarios and devices.

Keywords: IEC 60318-1, ear simulator, supra-aural earphones, circumaural earphones, acoustic transfer impedance, electroacoustics, audiometry, telephonometry, earphone measurement standard, calibration, acoustic coupler, frequency range, measurement uncertainty, IEC standards.