1、 Theoretical noise reduction limit of soundproof rooms
1. Laboratory level soundproof room
-Top level anechoic chambers (such as acoustic laboratories) can achieve insertion losses of 40-50 decibels (dB) (i.e., internal and external sound pressure levels)
-Specially designed double shell soundproof rooms (such as aerospace grade) can even reach over 60 dB, approaching the human auditory threshold (0 dB)
 
2. Industrial grade soundproof room
-Conventional soundproof rooms typically isolate 25-35 dB and are suitable for noise reduction in factory equipment
-By using composite sound insulation materials such as lead plates and damping layers, the noise level can be increased to 40 dB
  
2、 Isolation effect of different types of noise
1. High frequency noise (such as screaming, metal collisions)
-Easy to isolate, a single-layer soundproof room can reduce noise by more than 30 dB
2. Low frequency noise (such as elevator operation, traffic vibration)
-It needs to be combined with floating flooring and spring shock absorbers, with the best effect of about 15-20 dB

3、 Breakthrough Technology Cases
-The "Super Soundproofing Module" developed by the Fraunhofer Institute in Germany:
Nanoporous ceramic+aerogel interlayer is used to isolate the noise of 500Hz up to 55 dB
-Boeing Aircraft Test Cabin:
Composite metal sound insulation layer+active noise reduction system, achieving full frequency band 45 dB noise reduction
 
4、 Choose Suggestions
If isolation is required:
-Ordinary conversation sound (60dB) → Choose a 30dB soundproof room (reduced to 30dB, equivalent to a library environment)
-Electric saw sound (110dB) → requires a soundproof room with a noise level of 50dB or above (reduced to 60dB, equivalent to a normal office)
 
Note: The actual effect needs to consider background noise. For example, when the nighttime environmental noise is only 30dB, the soundproof room needs to increase by an additional 10dB to achieve "completely silent" perception.