ISO 389-5:2006

Overview

ISO 389-5:2006 is an international standard developed by the International Organization for Standardization (ISO) that specifies reference equivalent threshold sound pressure levels (RETSPLs) of pure tones in the frequency range from 8 kHz to 16 kHz. This standard is part of the ISO 389 series, which establishes reference zero levels for the calibration of audiometric equipment.

The core aim of ISO 389-5:2006 is to provide standardized RETSPLs for the accurate calibration of air conduction audiometers, focusing on specific models of earphones. By providing precise reference levels, ISO 389-5:2006 ensures consistency and reliability in hearing threshold measurements across audiometers worldwide.

Key Topics

• Reference Equivalent Threshold Sound Pressure Levels (RETSPLs): Specifies RETSPLs for pure tones between 8 kHz and 16 kHz, crucial for extended high-frequency audiometry.
• Earphone Calibration: Details the required RETSPL values for calibrating air conduction audiometers when used with select earphone types, including insert and circumaural models.
• Test Earphones and Configurations:
  • Insert earphone: ETYMOTIC RESEARCH ER-2 (with eartips type ER1-14A)
  • Closed-type circumaural earphone: SENNHEISER HDA 200
• Calibration Equipment: Outlines use of specific ear simulators (such as IEC 60318-1 and IEC 60711) and adapters for accurate calibration.
• Temperature Effects: Notes the importance of temperature in calibrating certain earphones (e.g., SENNHEISER HDA 200) to ensure stable measurements.

Applications

ISO 389-5:2006 is essential for several practical applications:

• Audiometer Calibration: Enables accurate calibration of audiometric devices used in clinical and research settings, especially for high-frequency air conduction audiometry.
• Quality Control in Audiology: Assists audiologists and device manufacturers in ensuring that hearing tests are consistent and comparable globally, improving diagnostic reliability.
• Research in Hearing Science: Provides a standardized basis for extended high-frequency auditory research, contributing to better understanding of hearing loss and hearing protection.
• Development and Testing of Earphones: Useful for manufacturers developing earphones and audiometric devices targeting accurate high-frequency sound reproduction and assessment.

Related Standards

ISO 389-5:2006 is part of a larger framework of standards addressing audiometric calibration and acoustics, including:

• ISO 389-1: Reference equivalent threshold sound pressure levels for pure tones and supra-aural earphones
• ISO 389-2: Reference equivalent threshold sound pressure levels for pure tones and insert earphones
• ISO 389-8: Reference equivalent threshold sound pressure levels for pure tones and circumaural earphones
• IEC 60645-4: Audiometers - Equipment for extended high-frequency audiometry
• IEC 60318 series: Electroacoustics - Simulators for human head and ear, including methods for calibrating different earphone types

These standards together provide a comprehensive foundation for the calibration and operation of audiometric equipment across a wide frequency range, supporting consistency and quality in hearing assessment worldwide.

Keywords: ISO 389-5:2006, acoustics standard, audiometer calibration, reference equivalent threshold sound pressure levels, RETSPL, high-frequency audiometry, air conduction earphones, hearing threshold calibration, audiometric equipment, ISO standards in audiology.