Why your video sounds echoey

You play the take back and you are further away than you were. The words are all there and something is smeared behind them, as though you had recorded at the end of a corridor. Turning the volume up makes it worse, which is the first clue.

The fix, before the explanation: get closer to the microphone. Rooms that sound echoey on camera are usually rooms with a microphone too far from a mouth, and moving it in costs nothing.

Where the echo comes from

Your voice leaves your mouth in every direction at once rather than in a beam. A small part of it travels straight to the microphone. The rest hits a wall, the ceiling, the floor, the window, the desk, and comes back.

Sound covers about a third of a kilometre every second, so the copy that bounced off the wall behind you arrives a few thousandths of a second after the one that went direct. Your ear reads that as a smear on the first rather than as a second sound, and they keep arriving, each quieter and later than the one before. That is what you are calling echo. The proper word is reverberation: your own voice turning up again after a detour.

Which tells you what it is not. Noise is something else making a sound: a fridge, a fan, a buzz in the mains. Reverberation is you. There is nothing in that recording which is not your voice, which is exactly why software finds it so hard to take out.

Why does a better microphone not fix it?

A microphone records both direct and reflected sound. Its polar pattern and placement affect the balance, so a different microphone can help, but a higher price alone does not solve the room. Try a closer position and listen before buying.

What decides whether a recording sounds close or distant is not the level. It is the ratio between the direct sound and the reflected sound. Raising the level lifts both by the same amount, so the ratio does not move and neither does the problem. Moving closer lifts mainly the direct half: halve the distance and the direct sound arrives far stronger, while the reflections, having bounced off the same walls in the same room, come back at very nearly the strength they always did. That is physics rather than a product feature, and it is why the free fix beats the paid one.

What should you change first?

In order of effect. Stop when it sounds right.

1. Move the microphone closer and check for plosives or handling noise. 2. Try a position away from prominent hard surfaces. 3. Test suitable soft furnishings or absorbers where reflections matter. 4. Compare another room if practical. Listen after each change; no furnishing absorbs every frequency equally.

Save the positions and a short reference recording once the setup works. Recheck after the room, microphone or recording arrangement changes.

Should you buy a de-reverb plugin?

Not first, and not as the whole answer.

De-reverberation can reduce room sound, but pushed too far it may shorten word endings or make the voice sound watery. Compare a short processed section with the original and stop where the trade becomes distracting.

Used gently on a recording that was already reasonably close, it is a real rescue. Used to save a voice recorded across a bare room, it removes part of the person along with the room, and a slightly live recording left alone is easier to listen to than a heavily dried one.

Is it echo, or is it hiss and hum?

Record ten seconds of silence at the top of every take, before you say anything, and listen back to those ten seconds on headphones with your eyes shut. It is the most useful ten seconds in home recording.

A steady tone, a wash of hiss or a low rumble while nobody is speaking is noise rather than echo, and it has a different and much easier fix, set out in Hum, fans and the fridge. If those ten seconds are properly quiet but your speech trails and blooms the moment you start talking, the room is what you are hearing.

If both noise and reverberation are present, test the processing order on a short section. Judge the combined result rather than assuming one sequence works for every recording.

Where this stops being about a plugin

There is a point at which the room stops being a technical problem and becomes a question about where you film. A voice recorded close in an ordinary living room, curtains shut and a rug down, needs almost nothing done to it afterwards. The same voice recorded two metres away in a hard room will absorb an hour of somebody's attention and still not sound as good.

So the decision is whether the room you film in is the room you should be filming in. No plugin settles that.

Sources and evidence

What here is established acoustics and what is our own method.

What is established. Whether a room reads as echoey depends on the balance of direct to reverberant sound rather than distance alone, the relationship the Institute of Professional Sound sets out as critical distance. How a microphone's tone changes as it comes in closer is the proximity effect, documented by DPA Microphones and dependent on the microphone's polar pattern.

Our method. Moving the microphone in before treating the room, then confirming by ear on playback, is a working default here rather than a law.

References.

• DPA Microphones. Proximity effect in microphones explained. dpamicrophones.com. Distance response depends on microphone design and polar pattern. Manufacturer education.
• Institute of Professional Sound. Critical distance. ips.org.uk. Room sound depends on direct-to-reverberant balance, not distance alone. Technical reference, not peer-reviewed research.