Without microphone cartridges

The GRAS RA0038 Coupler is a standard 2 cm³ Coupler according to IEC 126 and ANSI S3.7-1973. It uses a ½" microphone (preferably the GRAS 40AG) with a suitable preamplifier (e.g. GRAS 26AC which is a ¼" preamplifier but is supplied with an adapter for ½" microphones).

The GRAS IEC 318 RA0039 Ear Simulator is an ear simulator with an input impedance closely resembling that of an average human ear. When the RA0039 is coupled to a sound source, the impedance will load the sound source similar to the loading caused by the human ear. The RA0039 meets the requirements of IEC 60318-1:1998 Electroacoustics - "Simulators of human head and ear - Part 1: Ear simulator for the calibration of supra-aural earphones".

The GRAS RA0056 Low-leak Pinna Simulator is an outer ear simulator intended to be used with the Ear Simulator RA0045 to simulate a complete ear for testing telephones and loudspeakers

The High-leak Pinna Simulator Type RA0057 is an outer ear simulator intended to be used with the Ear Simulator RA0045 to simulate a complete ear for testing telephones and loudspeakers.

The GRAS RA0075 is a 6cc coupler for testing earphones according to ANSI 3.7 - 1995 and IEC 60318-3.

The GRAS RA0076 is a thread adapter to use when mounting a 1" or a 1/2" microphone in the RA0075 NBS 9-A Coupler. In the case of a 1/2" microphone the RA0077 1/2" - 1" Adapter for Coupler is also needed.

The GRAS RA0113 is a 2cc IEC 60126 coupler which uses a 1" microphone, e.g. the GRAS 40EN.The microphone, without its protection grid, screws into the base of the RA0113.

GRAS RA0252  is a1/4” 0.4cc High freq Coupler for testing of hearing aids at frequencies up to 16 kHz.