Soundproof or Sound-treated Studio? What You Are Actually Hiring

Search for a soundproof studio and you will find rooms described as soundproof, sound-treated, acoustically treated and isolated, often in the same listing. They are not the same thing, and the difference decides whether the take you record on the day is the take you keep. This guide separates the two ideas, explains what each one does for dialogue, podcasts and music, and lists the questions that get you a straight answer before you book.

Two different problems

A room can fail a recording in two ways. Sound can get in from outside — traffic, a door, footsteps, a neighbour's drill — and land on the track as noise you cannot remove without damaging the voice. Or the room itself can add to the sound: hard parallel walls bounce the voice back to the microphone a fraction of a second late, and the recording sounds hollow, boxy or echoey even when the building is silent.

Soundproofing, more precisely called sound isolation, deals with the first problem. Acoustic treatment deals with the second. A room can have one without the other, so before blaming a room for not being "soundproof", work out which of the two problems you are hearing.

What soundproofing actually is

Isolation is a matter of construction. Sound travels through air gaps and through the structure of a building, so stopping it takes mass, airtightness and separation: heavy walls, sealed doors, and ideally an inner room that does not touch the outer one, so vibration has no solid path in. That last approach is called a room within a room, or a floated room, and it is the construction behind rooms built for recording.

Isolation is never total. Even a well-built room lets some very loud or very low sound through, which is why a figure for how much a room reduces noise means more than the word silent. If a listing says "fully soundproof" without saying how the room is built, ask.

What acoustic treatment actually is

Treatment changes what happens to sound inside the room. Absorbent panels and foam soak up reflections so the voice reaches the microphone once rather than several times; bass traps deal with the low build-up in corners; diffusers scatter sound so the room feels less dead. Treatment does very little to stop outside noise, because soft materials are light and sound goes through them.

That is why a room covered in foam can still pick up a passing lorry, and why a heavy concrete room with no treatment can be perfectly quiet and still sound terrible on a voice.

Which one each job needs

• Dialogue for film and video: both. A line recorded in sync on set has to be free of outside noise and free of room sound, or it goes to ADR.
• Podcasts and talk shows: treatment first. The microphones sit close to the voices, so a treated room with sensible isolation can sound finished; an untreated one rarely does.
• Voiceover and narration: both, in a small space. A treated vocal booth is the standard answer, because the voice is the whole product.
• Music recording: both, and the treatment matters for monitoring as well — the engineer has to trust what the speakers are telling them.
• Photography, and video with no live sound: neither. Playback for timing does not need a quiet room, and paying for one buys nothing.

How the rooms at Scope compare

Studio B is built as a room within a room and sound treated, which is the construction used both to keep outside noise out and to stop the room adding its own echo. It is where dialogue, interviews and voiceover are recorded in the open room. It also blacks out, so the same room controls light and sound at once. Two hours is £120, a half day £220 and a full day £420.

The podcast room is acoustically treated and camera-ready, with professional microphones and audio interfaces already in place, at £80 for two hours and £30 for each extra hour. The music studio is panelled and foam treated, with a treated vocal booth and a large-diaphragm condenser, booked in four- and eight-hour blocks, dry from £80 a half day or with an engineer from £140.

Studio A is not a sound-treated room. It is the room for scale, blackout and the white drive-in cove, and we would plan any scene with dialogue for Studio B, or record the lines wild in the vocal booth. We have not published isolation figures for any room, so tell us what you are recording and the team will tell you honestly whether the room suits it.

Questions to ask any studio before you book

• How is the room built — a room within a room, or treatment on the walls of an ordinary room?
• Is the treatment in the room you will record in, or in a booth next to it?
• What is on the other side of the walls during your booking, and is anything noisy scheduled?
• Is there air conditioning or ventilation, and can it be turned off for takes?
• Can you hear the room before you commit — a test recording or a sample from a previous session?

Whatever the answers, record a few seconds of the silent room at the start of the day. That room tone is what the editor fills gaps with, and it is the fastest way to hear whether the space is as quiet as the listing said.

Common mistakes

• Booking the biggest room for a dialogue scene and discovering it was built for picture, not sound.
• Hanging blankets in an untreated room and expecting them to stop outside noise; they soften echo but stop very little noise.
• Paying for a sound-treated room for a stills shoot that never records a word.
• Leaving fridges, fans and phones on during takes in a well-isolated room, then blaming the room.
• Forgetting that the microphone position matters as much as the room: a close, well-placed mic in a treated space beats a distant one in any space.

For the sound side of a shoot in more depth — sync, wild tracks and ADR — read sound for video in a studio. For when a full sound stage is and is not worth it, see what a sound stage is.