How to reduce room echo in a voice recording.
A bare, hard-walled room keeps every word ringing for half a second or more after it's spoken. That ringing makes a voice sound distant and tired. You can take a good part of it down afterwards. Treating the room is still the bigger win.
What you're hearing
Sound bounces off walls, floor and ceiling. The first reflections arrive within a few hundredths of a second and blend with the voice; they give it body. The later ones are the ringing tail that fills the pauses and smears the end of words. How long a room rings is its decay time: a furnished living room might ring for 0.3 seconds, an empty room with a hard floor for 0.8 or more.
Fixing it afterwards
De-reverb tools predict the ringing from what was just said and how fast the room dies away, then turn down only that part, moment by moment. Done gently, the voice comes forward and the pauses get quieter, without the thin, underwater sound of overdone noise reduction.
- Be moderate. Taking the tail down by about 6 to 10 dB is usually the sweet spot; more starts to change the voice.
- Do it before compression and levelling, which bring the tails up.
- Don't expect a cathedral to become a booth. If the echo is louder than the voice, no tool will make it sound like a studio.
In the Gain Curve app, Voice mode has an Echo knob in the Voice group: 50 % takes the ringing down by up to about 10 dB, 100 % by up to 18. When you open a file, it measures how long the room rings and says so.
Recording with less echo
- Get closer to the mic: a hand's width away, the voice is much louder than the room.
- Use soft things: a sofa, curtains, a rug, a full bookshelf, a duvet hung behind the mic. A closet full of clothes is a classic booth.
- Avoid the middle of an empty room and record facing into the soft side.
- Dynamic mics pick up less room than condensers.
Paul Voia-Tipei, PVT Studio