Features:
- Accurate and very consistent simulation of human voice field
- Built-in class D amplifier
- Continuous SPL of 110 dB at 25 mm from lip ring
- Low distortion
- Built-in overload protection circuit
- Optional regulating microphone for very accurate frequency response control
- Calibration jig included
- Conforms to standards: IEEE-269, IEEE 661 and ITU-T Rec. P.51
- Low sensitivity to temperature and humidity changes
Uses
- Quality control testing of frequency response and distortion of telephone transmitters and close-talk microphones
- Sound source for acoustic measurements
The Mouth Simulator Type 4227-A is a high performance artificial mouth conforming to ITU-T Rec. P.51 and designed for accurate and repeatable electroacoustic measurements. The mouth simulators produce a guaranteed minimum continuous output of 110 dB SPL at a distance of 25 mm from the lip ring. A sound pressure level of more than 120 dB is possible with pulsed operation. A built-in overload-protection circuit minimizes the risk of accidental damage to the loudspeaker. A microphone can be fitted at the mouth opening for use in a compressor loop to give constant sound pressure output.
The mouth simulators are high-performance, low-distortion sound sources used for testing acoustic transducers. They consist of a high-quality loudspeaker mounted in a specially shaped housing. A lip ring is mounted on the upper surface of the unit, providing a convenient reference plane for measurements. Type 4227-A has a built-in class D amplifier which simplifies setup and minimizes thermal output, allowing use of the mouth simulator in small test chamber installations while avoiding heating of tested components.
When testing telephone transmitters and close-talk microphones, it is required that the sound field closely replicates the sound field generated by the human mouth, as specified in IEEE 269 and ITU-T Rec P.51 as fulfilled by Type 4227-A.
| Manufacturer | Bruel & Kjaer |
|---|---|
| Condition | Used |