What are room acoustics?
Room acoustics is science of understanding sound and it's behaviour in a given room. Different room types will demonstrate different room acoustics. For instance, rooms that are cube shaped, and are constructed with flat hard surfaces will enable sound, to reflect, creating echo and reverb.
What is the nature of sound in a room? Why are some rooms so loud?
When someone talks, in an open field, that sound can travel for hundreds of yards on a still day. That sound is said to have energy and momentum.
When you bring that sound/energy and trap it in a room, it still has momentum, and reflects, (bounces) off of hard surfaces much like a ping pong ball. A sound can reflect from flat surface to flat surface, thousands of times, before losing momentum.
The momentum from one spoken word, can bounce off walls and ceilings for up to 10 seconds, before decaying. See this example of a hand clap in an empty squash court. https://www.youtube.com/watch?v=B0_Dva7YVlc (and below).
Sound that reflects from surface to surface generates reverberation. Sometimes this reverberation can be understood as echo. The human brain interprets reverberation, as as muddy and unclear sound. This can cause listener fatigue. There is a difference between an echo and reverb,
The acoustic science of panel and diffusor placement.
How do acoustic panels work?
What is the formula to figure out how many acoustic panels I will need?
A simple formula is to multiply the room's volume by .03. That will give you the square footage of acoustic panels you will need. This page will help you calculate how many acoustic panels you may need to dampen the noise in your office or restaurant.
For instance, a room 10 feet high x 10 feet wide x 10 feet long is 1,000 cubic feet. The math will be 1000x.03 = 30 square feet of acoustic panels.
In this scenario, you will need about 30 square feet of acoustic panels. This could be one 4 ft x 8 ft panel or four 2 ft by 4 ft panels.
Do I need thick acoustic panels?
Are acoustic panels more effective on walls or ceilings?
In a perfect scenario for instance, the ceiling and two perpendicular walls would be addressed. This would address 3 of the 6 surfaces, their parallel planes would not need to be addressed.