scope:

General

This standard specifies relevant requirements for sound-field hearing tests conducted with the signals presented by means of loudspeakers in free, quasi-free, and diffuse sound fields. The requirements and conditions described in this standard are suitable for both frequency-specific hearing tests and assessment of detectability of wide-band signals. Two types of frequency-specific test signals-frequency-modulated tones and narrow-band noises-are described in the standard but other well-defined narrow- and wide-band test signals may also be used if the test conditions described in the standard are met. The main body of the standard specifies requirements for the measurement of the threshold of hearing. In addition, Annex B provides information about extending requirements of this standard to spatial hearing audiometry and directional hearing tests conducted for research purposes.

The requirements of the standard apply to hearing tests conducted in quiet. However, they also may serve as guidelines for similar sound tests conducted in the presence of other acoustic signals. If any form of acoustic masking or interference is introduced in the test, all specific information about the masking signals, their levels, and the delivery conditions shall be recorded and included with the test results.

Purpose

The purpose of ANSI/ASA S3.52 is to ensure that sound field tests of hearing, and particularly tests of hearing threshold, performed on the same individual in various clinics and laboratories shall give accurate and reproducible results. The test conditions and test stimuli described in the standard are applicable to all populations of subjects including children (play audiometry, visual-reinforced audiometry, and conditioned orientation reflex audiometry) and special listeners who do not tolerate earphones.

Applications

The main application of the standard is determination of hearing threshold levels in the frequency range from the 125 Hz to 12500 Hz range with possible extension to the 20 Hz to 18000 Hz range. The standard applies to both sound field audiometry and sound field research studies based on measurement of hearing threshold. The requirements of the standard apply to measurements made with stationary systems consisting of signal-generating circuitry, such as an audiometer, and one or more loudspeakers. In addition to threshold of hearing measurements, the standard may be used to determine the effects of hearing aids (e.g., functional gain), assistive listening devices, and various types of headgear on audibility of the test signals. The standard does not apply to sound field tests conducted with a handheld loudspeaker or conducted in virtual reality environments. Qualification tests for hearing protection devices should be made in accordance with ANSI/ASA S12.6 and ANSI/ASA S12.42 standards.