Before you go down the avenue of re-flashing or factory reset, try this:
Before going and changing the network modes, try booting the phone in Safe Mode, by going to Shutdown with Power Button, and then Press and hold Shutdown until a popup dialog appears to restart in SafeMode.
Also try a test in Ultra Stamina Mode.
- Find out what your service provider uses for their mobile network
- Call Tech Support or go in to a retail outlet
Dial *#*#7378423#*#*
This will take you to the service menu. We won't need to change anything here for now, but use information for reference.
In service menu:
SERVICE MENU » Service Info » Configuration
Ask the Tech the available "Working Bands", note "Speech Codecs" for explanation below
Most countries will have a high-speed network, something in the middle, and some really old stuff. Going fast to slow:
4G > > > 3G > > 2G > WAP
LTE > HSPA+ > HSDPA > UMTS > EDGE > GPRS > GSM
Those two lines are the same but just using different names
Depending on the network, the device chooses the best band, then when using voice, selects an appropriate speech codec..
What we are going to try to find is if this problem is happening atna specific band or operating parameters. I don't think this had really been looked at in the other thread about echo during calls.
We need to check if the problem occurs in a specific mode by forcing it in the service menu
SERVICE MENU » Service Setting » Network Mode
The easiest to check first is
GSM Only and also LTE Only, if it is available to you.
The other checks start to get more complicated because of the crossover of compatibility between the bands and the speech codecs around the 3G(UMTS)
HR, FR, EFR, AMR_HR, AMR_FR are on the older 2G(GSM)
Then you have the UMTS equivalent on 3G and above, by selecting LTE Only, we can force the UMTS_codecs to be used
See if there are any significant difference in call quality.
In radio transmission there are feedback loops, and also loops for audio signals and amplification or modification.
There's a few apps that would have access to this...
Check main: Settings » Accessibility
In here try to eliminate and disable as much as we can to isolate the source of the echo. Mono Audio will use the audio mixer, so try settings with it disabled and enabled.
Text to Speech ... another setting that can influence signal flow if behaving incorrectly.
Outside of Accessibility you have Googles TTY and Sony's found in: Call » Call Settings Accessibility
EDIT: AFTER SEEING PRINT SPOOLER USE LOCATION SERVICES, I DONT COUNT ANYTHING OUT ANYMORE. I HAVE NFI WHY. WHO KNOWS WHO CARES, ILL JUST TEST
One of the other 'maybe/variables' is the automatic microphone gain in Settings » Sound » Accessory Settings, try calls with Auto, High, Med, Low.
We have to check any possibility of the effect on call quality, if any of these apps are misbehaving.
If you want a visual example of feedback looping, if you have two phones, call one make them face each other, flip one to make it mic to speaker and speaker to mic. Then make a call, and once it connects, say Hello or whatever. You'll be able to hear what you said bounce between both the phones, either getting louder or softer or distorting and bouncing and bouncing... but basically the audio sample goes around in circles. when feedback is really bad, the signal either clips or goes around so fast... you get that high pitched squeal starting
EDIT: IF YOU WANT SOME FUNKY DOODADS. USE BOTH PHONES AT THE SAME TIME ONE TO EACH EAR
this is a gross example of what you are hearing and
This is either happening on/at
- your device
- the network tower relays when the signal passes through their systems
- the other device
Trying to find the cause of these types of things **bleep** when so many other things could be involved... I don't like doing it
