How to record clean audio with your phone: 12 tips

Why the recording matters more than the cleaning

Every noise remover works on the gap between your voice and the noise around it, the signal-to-noise ratio. The wider that gap, the less the cleaning has to take away, and the more natural your voice stays. In our lab test, steady noise was removed at every level we tried, but when the noise was as loud as the voice, the cleaned voice came out thinner. How we measured.

Echo is the other reason: it is your own voice coming back from the walls, and no denoiser can separate it from you. It can only be avoided while you record.

Place the microphone

1. Get within a hand span

Hold or place the phone about a hand span from your mouth, 15 to 20 cm. Sound weakens as it spreads: each time you halve the distance, your voice reaches the microphone about 6 dB stronger, while the fan or the street stays exactly as loud. Moving from arm’s length to a hand span gains roughly 10 dB over the background, enough to make the background sound about half as loud. Don’t go much closer: within a few centimetres, p and b sounds pop, so speak slightly across the phone rather than straight into it.

2. Speak to the right microphone

Most phones have two or three microphones. The one used for voice is usually on the bottom edge, near the charging port; the others help cancel noise during calls and videos. Speak toward the bottom edge, and keep your fingers and the case away from its small opening. Not sure which one your phone uses? Make a test recording and scratch lightly near each opening: the one that sounds loud is the one in use.

3. Put the phone down

A phone in the hand picks up every shift of your fingers, a ring tapping the case, a thumb sliding on the screen. Prop it on a small stand or a stack of books at mouth height. A folded towel underneath keeps the table’s vibrations (a bumped desk, typing) out of the recording.

Choose the room

4. Pick the softest room you have

Hard surfaces bounce your voice back to the microphone a fraction of a second late, and that is what sounds like echo. Soft, uneven things absorb it: curtains, a sofa, a bed, cushions, rugs, full bookshelves. A walk-in closet full of clothes is one of the driest places in a home; a furnished bedroom comes next.

5. Turn off what hums, just for the take

Fans, air conditioning, the fridge, a heater, a dehumidifier: switch them off for the few minutes of the recording, and close the window on the street side. Noise Remover removes steady noise like this well, as the fan noise page shows, but every decibel you don’t record is one the cleaning doesn’t have to take out. If a machine has to stay on, put distance between it and the phone.

6. Stay away from bathrooms and bare walls

Tiles, glass, bare walls and empty rooms ring like a bell: avoid bathrooms, kitchens, stairwells and freshly emptied flats. In any room, don’t speak into a wall or a window up close; face into the room, toward the soft furniture, and stay out of corners, where the low frequencies pile up.

Prepare the phone and the gear

7. Turn on airplane mode or Do Not Disturb

A notification chime, a vibration on the table or an incoming call can ruin a good take. Turn on Do Not Disturb, or airplane mode if you won’t need the network; with some phones and wired microphones, airplane mode also stops the faint buzz that radio bursts can induce in a cable. Noise Remover cleans offline, so airplane mode doesn’t get in its way.

8. Use a clip-on microphone if you have one

A lavalier clipped to your collar stays a hand span from your mouth wherever you turn your head, which is why interviewers use them. A wired one, with a 3.5 mm or USB-C plug, sends full-quality sound to the phone. A Bluetooth headset or earbud is more convenient, but it usually carries the microphone over a hands-free link designed for calls, which compresses the voice and can make it sound thin, like a phone call. Wireless kits that come with their own USB-C receiver behave like a wired microphone.

In Noise Remover, you choose the microphone before you record, on Android 10 or later: the phone’s own, a wired or USB microphone, or a Bluetooth one.

9. Shield the microphone from wind

Wind hitting a microphone makes low, rumbling bursts that can overload it. Outdoors, turn your back to the wind so your body shields the phone, record in the lee of a wall or a parked car, and fit a foam or furry windscreen on an external microphone. Noise Remover handles moderate wind well (see wind noise), but a gust that overloads the microphone stays distorted.

Record the take

10. Leave headroom: clipping can’t be undone

When the sound is louder than the microphone or the converter can handle, the tops of the waveform are cut flat. That is clipping, heard as a harsh crackle, and the part above the limit is simply gone: no tool can bring it back. Watch the level meter while you say your loudest line (a laugh, an emphatic word), and if it touches the top, move back a little or speak a bit softer. A recording that is slightly quiet can be brought up; one that clipped cannot.

11. Make a 10-second test

Before the real take, record a sentence or two in the exact setup and play it back on headphones. Listen for hiss, hum, echo, popping p’s, a muffled microphone and clipping. Ten seconds of checking can save a take you can’t repeat: an interview, a lecture, a moment.

12. Record a few seconds of room tone

Room tone is the sound of the room with nobody speaking. Ten to thirty seconds of it, recorded at the start or the end of a session with everyone still, helps in editing: editors use it to fill gaps and smooth the cuts. Noise Remover doesn’t need it, though. Unlike older noise-reduction tools that learn the noise from a sample, its engine tells speech from noise on its own, every 10 ms, and follows the noise as it changes.

Then clean what’s left

Even a careful recording carries some noise: a distant road, a fridge two rooms away, the hiss of the microphone itself. Record straight into Noise Remover, or open the file afterwards, and the cleaning starts on its own; the full walkthrough is in how to remove background noise on Android. If the voice still sounds far away after cleaning, the room is the cause: see echo or background noise?.