Anyone else have this issue?
I tried two sets of head phone. The mic is super sensitive. Too sensitive to be able to use. Have not tried Bluetooth yet.
This is NOT just you.
I have the exact same issue.
The same phone. *Pixel 4a
I was on a call, using a wired headset when I noticed I could update to 13.
Set the phone on my desk and I did the update.
I called the person back after the update was completed and what you described happened.
What is going on is the microphone on wired headsets stays "live".
During a call, I hear everything the microphone hears.
The person I am talking to still has background noise suppressed.
Whereas I dropped a TOOTHPICK and heard it hit the carpet.
Imagine a true wireless earbud with Ambient Sound turned up to 11.
It reminds me of the accessibility option where it picks up all the sound around you so you can hear it.
I have used 2 dialers besides the stock Google Dialer.
I have tried 4 brands of wired headsets and one in-ear monitor.
One of which was new in the box purchased a month ago.
I used canned air.
Gently clean the port with a toothpick in case of debris.
I took most of the cotton off a Q-tip so it would fit the 3.5mm (it retains a bit of cotton) and used it to clean the port using 91% isopropyl alcohol.
I took an electronics cleaner (CRC brand) for circuit boards and one of those little Dental Brushes made as a dental floss substitute and very, very gently cleaned the terminals in the 3.5 port on my Pixel 4a to make sure they were not gunked up.
I now have an extremely clean 3.5 mm port.
I also STILL hear everything in the world that headset mic pics up.
It ONLY does this on a phone call. (also tried wifi calling. still happened)
I tried Teams, Zoom, Discord, and Skype and this did NOT happen.
It is, without a doubt, an Android 13 issue.
Someone did not follow best practices.
At a casual glance, I see 13 has a new external audio route with a new API.
That is my best guess.
EDIT: I set up a Google Voice number on my Pixel4a and found something interesting.
When Google Voice is set to Use Carrier Only where it only uses my cell phone carrier I have the above 'hot mic' microphone issues. Incoming and outgoing.
When Google Voice is set up to Prefer Wi-Fi and mobile data I have no microphone issues whatsoever. Incoming and outgoing.
Same phone.
Same wired headset.
The reverse isn't true.
Using my cell phone carrier instead of Google Voice, I get the 'hot mic' problem whether I am using wifi or cellular.