ISO 1683:2015

Overview

ISO 1683:2015 - Acoustics: Preferred reference values for acoustical and vibratory levels - specifies the internationally agreed reference values used to express acoustical and vibratory levels. The standard defines the baseline quantities (expressed as a number and an SI unit) used to form ratios for logarithmic quantities (decibels), and it establishes a uniform basis for reporting levels of airborne sound, sound in liquids and structure-borne sound.

Key topics and requirements

• Mandatory reference domains: Reference values are mandatory for airborne sound (sounds in air and other gases), sounds in water and other liquids, and for structure-borne sound; they may also be used in other applications.
• Reference-value principle: Reference values are expressed as “the number one” combined with an appropriate SI unit to form dimensionless ratios for logarithmic levels (dB). The chosen reference determines whether measured levels are numerically positive or negative.
• Common reference values (as given in ISO 1683:2015):
  • Airborne sound: sound pressure = 20 µPa
  • Sound power: 1 pW
  • Sound energy: 1 pJ
  • Sound intensity: 1 pW/m
  • Sound in liquids: sound pressure = 1 µPa (note: a 1 µPa reference gives ≈26.0 dB higher numerical value than a 20 µPa reference for the same pressure)
  • Vibratory quantities: displacement = 1 pm; velocity = 1 nm/s; acceleration = 1 µm/s; force = 1 µN
• Notation: The reference value used to establish a level should always be stated together with that level.
• Compound quantities: ISO 1683 also shows how distance and compound quantities (e.g., sound pressure × distance) form reference values (e.g., µPa·m), supporting consistent reporting across derived measures.

Applications

• Standardizes the basis for reporting sound pressure levels, sound power, sound intensity, sound exposure, and vibratory levels in:
  • Environmental noise assessment and regulation
  • Underwater acoustics and marine monitoring
  • Product noise testing and certification
  • Machine vibration and structure-borne sound analysis
• Ensures consistency in published measurements, legal specifications, test reports, and engineering documentation where decibel-based quantities are used.

Who uses this standard

• Acoustical engineers, laboratory technicians, metrologists and test houses
• Environmental consultants, regulatory bodies and compliance officers
• Marine acousticians and vibration specialists
• Manufacturers requiring consistent acoustic and vibratory reporting

Related standards

• ISO 2041 (mechanical vibration vocabulary - revision referenced)
• ISO/TR 25417 (definitions of basic acoustical quantities)
• ISO 80000-8 (quantities and units - acoustics)
• ISO/IEC Guide 99 (VIM - metrology vocabulary)

Keywords: ISO 1683:2015, acoustics standard, reference values, sound pressure, vibratory levels, decibels, airborne sound, underwater acoustics, structure-borne sound.