Perforated Panel Absorbers are for internal room acoustics. It absorbs the sound so that it does not reflect. In a home theater or in a conference room or in an auditorium we would use something like this to absorb sound so that it does not reflect.
In a home theater or in a conference room if this panels are not there, it will have impact on the Acoustic experience in the room.
For Home Theater
Typically to have an optimum experience the dialog should be coming from only one place; the sound should come from only one place. If you’re without any acoustic treatment the sound is coming from the speakers but then at the same time the sound is coming from a speaker which is say 8 ft from you. There’s a wall also next door, the same sound is also hitting the wall and coming to you. So that is coming to you with a slight delay of maybe 10 ms compared to the direct sound. So the direct sound is mixing with the 10ms delay plus from the ceiling it is reflecting with a 20ms delay plus from the floor it is reflecting with a 7ms delay plus from the left side wall. All these multiple reflections are combining and that makes the sound a bit of less clear. The definition is lost and you cannot clearly localize like its coming from there. For a surround sound movie that is important. Like somebody is standing on the left, the sound should come from the left. If you don’t have acoustic treatment for a home theater it affects this.
In an auditorium when you don’t have acoustic treatment it’s such a big room. so these reflections they interfere with the intelligibility people will not understand what you are saying. Suppose you say this “today we are going to talk about something” so when you say ‘today’ that echo of today will interfere with the direct sound when you are saying today. And the next word i.e. when you say ‘we’ the echo of the word today will mix with ‘we’. So the sound lingers in the room and that interferes with the next word it smears it all up. So that speech intelligibility is affected in large rooms not in a small room. In small rooms it is more critical like serious home theater, recording studio that is where the internal absorptions happens.
How is Perforated Panel Absorbers made
They might be just a fabric kind of thing with some acoustic core. Like a glass wool based board or an acoustic foam or rock wool. The thicker it is the more effective it is.
Is it required on walls & ceilings ?
It depends on the application. It’s not done on all the walls except the theater we would probably do it everywhere. In conference room it won’t be there everywhere it’s not really like a recording studio so we don’t need so much treatment in the conference room.