DS/ISO 389-7:2019

Acoustics – Reference zero for the calibration of audiometric equipment – Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions


Status:
Current
Type:
Standard
Language:
English
Price from:
€ 56.88

Scope

This document specifies a reference threshold of hearing for the calibration of audiometric equipment
used under the following conditions.
a) The sound field in the absence of the listener consists of either a free progressive plane wave (free
field) or a diffuse sound field, as specified in ISO 8253-2. In the case of a free field, the source of
sound is directly in front of the listener (frontal incidence).
b) The sound signals are pure (sinusoidal) tones in the case of free field conditions and one third
octave bands of (white or pink) noise in the case of diffuse field conditions.
c) The sound pressure level is measured in the absence of the listener at the position where the centre
of the listener’s head would be.
d) Listening is binaural.
NOTE 1 – Correction values for the threshold of hearing under free-field listening conditions and selected
angles of sound incidence (45° and 90°) deviating from frontal incidence are given in ISO 8253-2 for information.
NOTE 2 – Other conditions are given in Reference [1].
The data are given in numerical form for the preferred frequencies in the one-third-octave series
from 20 Hz to 16 000 Hz inclusive in accordance with ISO 266 and, in addition, for some intermediate
audiometric frequencies up to 18 000 Hz.
The threshold data differ from the audiometric zero specified in ISO 389-1, ISO 389-2, ISO 389-5 and
ISO 389-8, since the latter refer to monaural listening through earphones with sound pressure levels
referred to specified couplers and ear simulators. Direct comparison between the data in the parts of
ISO 389 mentioned above and in this document is therefore not appropriate.

Number of pages: 20

Published: 2019-12-05

Date of approval: 2019-12-03

International relationships : ISO 389-7:2019 IDT

ICS: 13.140 - Noise with respect to human beings

Item number: M335072


Committees

Committee

  • ISO/TC 43
  • ISO/TC 43/WG 1

Danish committee

DS/S-115