No sound can be heard in space because there's no medium for it to travel through. But inside China's space station, which serves three taikonauts as they live and work in space, the buzzing equipment can be a real nuisance.

Luckily, the noise is not a problem. To provide a tranquil and comfortable living environment for the diligent taikonauts, the research team on the ground has put in quite an effort to turn it down.

When the manned spacecraft is launched into space, the noise outside the craft can hit 140-160 decibels – 110 decibels is the pain threshold for the average human.

To check if the noise outside the spaceship will affect the taikonauts and operation inside, the research team developed a large testing environment to simulate all the deafening noise that may be generated during the flight and placed the newly built spaceship in the testing environment for a thorough test.

The Wentian lab module has three sleeping areas and multiple cabinets for experiments. It's also equipped with numerous apparatus, including compressors, pumps, fans, refrigerators for experiments and control facilities to manage the spaceship's position. When these machines start working, they generate a large amount of noise, which creates a complex sound environment.

The researchers used science to single out all the equipment that are too loud. For example, the refrigerator is one of the noisy equipment inside the Wentian module because it has as many integrated functions as possible.

Many noise-reduction materials cannot be used for noise-proofing in space because they may affect the air quality in the space station in the long run. The researchers had to design a new pump and noise-reduction materials.

As the equipment are different in aspects, including the size, location and the cause of the noise, the research team had to use diverse methods to reduce the noise, such as covering them with rubber or placing them inside soundproof boxes.

Thanks to their efforts, the noise in the work area in the Wentian module is maintained at under 60 decibels. It is 50 decibels in the sleeping area, which offers taikonauts a quiet environment to rest as they continue their work in space.

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