The short answer
Look at the mesh grille on the earbud. If it looks dull, waxy or discoloured, that is your muffled sound — clean it with a dry soft brush. If the mesh is clean, check whether a volume limit is switched on, and whether Bluetooth has dropped to a call-quality codec because an app is holding the microphone open.
Sound that goes dull, thin or quiet almost never means a blown driver. Drivers fail loudly — distortion, crackling, silence. Gradual muffling has a short list of mundane causes, and most cost nothing to fix.
1. The mesh is blocked
This is the most common cause by a wide margin. Earwax, skin oil and dust collect on the fine mesh covering the nozzle. The blockage builds gradually, which is why people describe the sound as having slowly got worse, and why one side often sounds different from the other.
To clean safely: remove the silicone tip and wash it separately in warm water, drying it fully. Brush the mesh with a dry soft-bristled brush, holding the bud face down so debris falls out rather than in. For stubborn wax, a little blu-tack pressed against the mesh and pulled away lifts it without pushing anything deeper.
2. A volume limit is switched on
- iPhone: Settings, Sounds and Haptics, Headphone Safety. Reduce Loud Sounds caps output at a chosen level.
- Android: Settings, Sound, then look for a media volume limit. Phones sold in the EU also warn and cap at a threshold each listening session.
3. Bluetooth dropped to a call codec
This one confuses people because it is dramatic and fully reversible. When any app activates the microphone, Bluetooth switches from a stereo music profile to a low-bandwidth two-way call profile. Sound becomes thin and quiet, as though the headphones broke mid-song.
The culprit is usually an app holding the mic open in the background: a voice assistant, a recording app, a game with voice chat, or a meeting app left running. Close it, or toggle Bluetooth off and on, and full quality returns immediately.
4. Equaliser and audio effects
Check whether an equaliser is applying a preset you forgot about — in the phone settings, in the headphone companion app, or inside the music app itself. Spotify, Apple Music and YouTube Music each have their own. Adaptive and ambient sound modes on noise-cancelling headphones also change tonality substantially.
Working through it
Compare left and right
Play something familiar and listen to each side alone. If one side is duller, that points at a blocked mesh on that side rather than a setting, which would affect both equally.
Clean the mesh and wash the tips
Remove the silicone tips, wash and dry them fully. Brush the mesh dry, face down. Use blu-tack for anything stubborn. Let everything dry completely before reassembling.
Test on a different device
Pair them to another phone or plug them into a laptop. If they sound correct there, the problem is a setting or an app on your original device rather than the headphones.
Check volume limits and equalisers
Turn off any loudness protection and set every equaliser flat, including the one in the music app and the one in the headphone app.
Rule out the call-codec drop
Close every app that might be holding the microphone, then toggle Bluetooth off and on. If the sound snaps back to full quality, that was the cause.
Update firmware, then reset
Check the companion app for a firmware update. If nothing has worked, reset the headphones and pair them fresh.
Isopropyl alcohol can dissolve the adhesive holding the mesh and driver assembly, and it carries dissolved wax inward. Clean the nozzle dry only. Water is fine for the removable silicone tips alone.
Frequently asked questions
Why do my earbuds sound quieter than they used to?
Almost always a blocked mesh from earwax building up over months. It is gradual, which disguises it. Cleaning restores the original output in most cases.
Why do my headphones sound terrible on calls?
Because Bluetooth switches to a low-bandwidth two-way profile whenever the microphone is in use. It is a limitation of the standard rather than a fault, and it affects every wireless model to some degree.
Can wired headphones get muffled too?
Yes, from the same mesh blockage, and additionally from a worn plug or damaged cable near the connector. If flexing the cable at the plug changes the sound, the cable is failing.
Is it safe to clean earbuds with water?
Only the removable silicone tips, dried completely before refitting. The bud itself must be cleaned dry, because liquid in the nozzle reaches the driver and does permanent damage.
Take the tips off and look at the mesh. That one check explains most headphones that have quietly got worse.
