G.R.A.S. 44AB Mouth Simulator according to ITU-T Rec. P51

ITU-T rec.: P.51
IEEE standards: 269, 661
  • 44AB Mouth Sim ITU-T P51

At the mouth reference point (MRP), which is 25mm from the detachable lip ring (35mm from the mouth of the Type 44AB), the maximum continuous signal it can produce in 1/3-octave bands is 100dB re. 20µPa in the frequency range 100Hz to 16kHz. Its loudspeaker accepts an external signal directly via a BNC input.

Jigs are included for calibration according to CCITT P.51 and IEEE 269. These are for use with ¼" or ½" microphones. One jig holds the microphone at 0º incidence (¼" only) to the sound source, the other at 90º incidence (¼" or ½").

Connector type BNC
ITU-T recommondations P.51
IEEE standard 269, 661
Maximum power, continuous W 10
Maximum power, pulsed 2 sec. W 50
Temperature range, operation °C / °F 10 to 35 / 50 to 95
CE/RoHS compliant/WEEE registered Yes/Yes/Yes
Weight g / oz 1000 / 35.274

Maximum continuous output level at MRP [200 Hz - 6 kHz] 110 dB re. 20 μPa

Maximum continuous output level at MRP [100 Hz - 16 kHz] 100 dB re. 20 μPa

Distortion 250 Hz - 8 kHz (Linear signal @ 94 dB at MRP) typically 1 %, max. 1.5 %

Frequency response


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