I wonder if that shares the same physics as silvent's compressed air guns.

Silvent’s air nozzles reduce the sound level when blowing with compressed air compared to blowing through open pipes. This is due in part to the reduction in noisy turbulence from using Silvent’s air nozzles, and also because of the nozzles’ special design. Silvent’s air nozzles pass the compressed air through small holes and slots, which raises the sound to frequencies beyond what the human ear can perceive. This allows us to make blowing with compressed air both quiet and efficient.

Could use an even quieter compressed air gun