An anechoic chamber is a special acoustic laboratory designed to provide an environment with almost no reflected sound waves, so that accurate acoustic measurements and noise testing can be performed. The interior of the anechoic chamber is covered with sound-absorbing materials, such as sound-absorbing wedges, which can absorb incident sound waves and reduce or even eliminate reflections and reverberation.

In the anechoic chamber, the following types of noise tests can be performed:

1. Product noise testing:
Test the noise level of various electronic equipment, mechanical equipment, automotive parts, etc.
Noise evaluation of fan coil units, air conditioning systems, motors, compressors, etc.

2. Acoustic performance testing:
Test the acoustic characteristics of audio equipment such as speakers, headphones, and microphones.
Measurement of parameters such as frequency response, distortion, and signal-to-noise ratio of sound playback systems.

3. Material acoustic property testing:
Performance evaluation of sound-absorbing materials and sound insulation materials.
R&D testing of new acoustic materials.

4. Noise source location:
Determine the main source of noise in complex equipment for noise reduction improvements.

5. Acoustic model validation: Validation of acoustic predictions based on physical models.

6. Speech recognition and communication system testing: Testing speech recognition systems, teleconferencing equipment, etc. without background noise.

7. Acoustic standards and specifications testing: Acoustic performance testing that meets international or industry standards.

8. Research and development: Basic acoustic research, such as sound wave propagation, sound wave interaction with matter, etc.

When performing these tests, the background noise in the anechoic chamber needs to be very low so that it does not affect the test results. Usually, the design and construction of the anechoic chamber will take into account the lowest background noise level, as well as the required frequency range and test accuracy.

If you need to perform specific noise tests, you should ensure that the anechoic chamber meets the frequency range and acoustic performance requirements required for the test. In addition, depending on the test object, specific fixtures or additional equipment that simulates the real environment may be required.