How Soundproofing Works
Real, honest-to-goodness professional soundproofing is highly expensive. It involves adding insulating materials and extra drywall—or replacing existing wall materials with new and more expensive materials. It’s a lot to contend with.Professional soundproofing also involves contractors and consultants and decibel meters: more expense.
Reduce Airflow, Reduce the Sound
But one trick that is used to cut down on the transmission of sound is to reduce airflow. Think of the room that you want quieter as having air flowing into it from the outside. How is the air escaping into your room? The gaps between outlet boxes and drywall are one area. Another area: gaps under doors. If the sound is coming from outside, airflow coming through or around windows is another place to look.It doesn’t seem like it should, but even these pencil-thin seeps of air carry sound. Remember, sound is caused by vibrations travelling through the air, right?
The same type of thinking that is used to detect cold air coming into your house is the same type of thinking needed to detect sound carried by airflow.
Imagine an incredibly thick, apparently soundproof wall. If that wall had a crack running through it, even it would transmit sound to the other side.

