In a professional or commercial recording studio, at least two rooms are devoted to the recording process. The control room holds all the equipment, such as the mixer, the computer, the outboard effects, and the monitor speakers. The control room is also where the engineer, producer, and other non-musicians (such as the client or record-company executive) hang out.
The studio, or live room, holds the musicians and has very little equipment in it other than microphones and whatever gear the musicians need to create their music. The studio is typically adjacent to the control room, separated by a wall with a large, multipaned window to allow visual communication between the musicians and the control room personnel. Verbal communication is accomplished electronically through the microphones in the studio (so that the musicians can speak to the control room) and through the musicians' headphones (which allows the control room, via a „talkback“ mic, to speak to the band).
Professional recording studios spend thousands of dollars to treat their rooms for soundproofing and acoustics. Home recordists who are serious about creating a neutral environment, and who have earmarked funds for this, might construct a floating room, insulate the four walls with special material, and purchase movable baffles. But more likely than not, you'll spend your money on more tangible items, such as a spare hard drive or a software-based sampler.
For our hypothetical room, we'll consider several approaches to taming sound, none of which costs very much money or requires that much effort or expertise. Even hanging a winter coat in the corner or facing an acoustic guitar toward an overstuffed couch instead of the wall can help you either reduce reflected sound or isolate an instrument when recording.
For the computer recordist, the philosophy of room sound is sort of a black-and-white proposition: If you can't make the room an acoustic paradise, then you want to deaden it almost completely and add any ambient treatment (such as reverb) after the fact (i.e., during mixdown), electronically. Because you'll be recording (which can require isolation) and mixing (which should be done in a neutral room), the best compromise is to go for a deadened sound.
It's important to clear up one key issue in matters of room sound: Soundproofing is an entirely different issue from sound treatment. Soundproofing deals with keeping outside sound out and the inside sound in. As simple as that sounds, it can be very difficult and expensive to achieve.