Room Acoustics are a commonly misunderstood factor in homes, sound systems, even 2 channel systems. The room is the final determinant of what you hear from any reproduction system. Yes improving placement of the speakers, even the equipment, can help with the sound, but ultimately the room determines what you hear. Research has shown that up to 80% of what one hears in music is the room, not the original sound from the speakers or the instruments. Speakers are some of the worst offenders as the tweeters and drivers tend to spray the sound out of the speaker in a 180 degree pattern-exciting the walls, ceilings, and floors. All of this sound bounces off these surfaces and winds up at your ear out of phase with the original signal. FYI-you can detect at your ear a phase difference of 1/3000 of a second at 500-4000 Hz-dead in the midrange where most music exists. Your ear is very good at discriminating direction and phase as well-so a note bouncing off the ceiling vs. a note directly from the instrument or speaker will not sound “right”. You can thank our ancestors and their survival skills for our hearing today. We really do need to know what it is and where it is so we can run from it and not be dinner. Unfortunately our hearing was developed for open spaces, not rooms. Hence the sensitivity to phase and direction.
There is also the interpretation of the sound that occurs in the brain. Ever notice how something sounds weird when you first turn on music then it sounds much better and more melodic a few seconds later? An excellent example of the brain in motion. The brain builds up a library of sound over your life, and then applies that to what you are hearing on a daily basis. Notice again how when you hear something new-you concentrate on it-to determine what it is (fight or flight response), then the brain files it for later reference. When you listen to music all of this comes into play. Research has shown that we tend to hear that that is familiar, not necessarily what is really being heard. Also our brain will filter out what is not important for us-this happens daily.
Next time I will talk a bit about room acoustics-the room itself.