Disclaimer: You accept all responsibility for yourself and your device if you use the information on this page. If you damage your phone trying this fix, that's on you.
Historical Note: This was written for the Samsung Galaxy S5 back in 2017. If you're still using an S5, this fix should still work. If you have a newer phone with similar issues, the same principle applies.
The Problem
People complain they can't hear you on phone calls. You sound distant or muffled. You've tried turning up the volume, but that's for the speaker, not the microphone.
You start Googling "how to turn up mic volume on Galaxy S5" and find out you can't adjust mic gain without rooting your phone.
Good news: There's probably nothing wrong with your mic volume. The mic hole is plugged with lint or dirt.
What You Need
- Small Phillips screwdriver (PH000 if you have it)
- Small sewing needle (use the back end if it fits)
- Compressed air duster (available at any electronics section)
How to Fix It
Step 1: Power Down
Turn off your phone completely. Remove the back cover and pull out the battery.
Step 2: Clear the Mic Hole (Optional, Risky)
This step is risky. Only do it if you're comfortable potentially breaking something.
Take the back end of the sewing needle and gently insert it into the mic hole. Try to loosen any visible lint or dirt.
Do NOT push if you feel resistance. You can easily destroy the microphone if you're not careful. If it feels stuck, skip this step and go to Step 3.
Step 3: Remove the Screw
Locate the small Phillips screw closest to the microphone hole. Remove it with your screwdriver.
Step 4: Blow Out the Obstruction
This is the key step. Take your can of compressed air and press the nozzle tightly against the screw hole you just opened.
Give it a couple of short bursts. You should feel air rushing out of the mic hole if it's clear.
Important: When using canned air, always keep the bottom of the can pointed down. If you tilt it, liquid propellant can spray out and damage your phone.
You can also try blowing into the mic hole with your mouth, but don't make a tight seal. Too much pressure can destroy the mic.
Step 5: Reassemble
Put the screw back in. Pop the cover back on. Insert the battery and power up your phone.
Step 6: Test It
Make a test call to someone. Ask them if they can hear you better.
If you did it right, the mic volume should be back to normal.
Why This Happens
The Galaxy S5 mic hole is tiny and sits at the bottom of the phone. Lint from your pocket gets packed into the hole over time, muffling the microphone.
It has nothing to do with software or gain settings. It's just dirt.
If This Doesn't Work
If clearing the mic hole doesn't fix it, you might actually have a hardware problem. At that point you're looking at a repair or a new phone.
But try this fix first. It takes five minutes and costs nothing.
Got Other Tech Problems?
I help with all kinds of tech issues, from phone problems to website troubleshooting. If you're stuck on something, reach out.