During a VoIP call, the volume (the audio I hear, not the volume bar) keeps going up and down. This strange phenomenon is most noticeable when the android volume bar is under ~3/4 from maximum. The variation diminishes when I set the volume bar to maximum.
I tested using another phone than Teracube 2e (Moto E5 Play). On the Moto, I do not have that fluctuating volume problem. Both phones were tested using the same internet connection. It is not an internet connection problem.
I tested using different VoIP softphones (Linphone, Jami). They both have this issue in Teracube 2e. It is not a softphones specific problem.
Here is what I did to reproduce the problem on Teracube:
Test 1
- Do: Open Linphone
- Do: Call echo test, (voip.ms is 4443)
- Do: Set android volume to maximum with the hardware buttons
- Do: Wait for the recorded voice to finish spelling the instructions if any
- Do: Say AAAAAAAAA for as long as you can.
- Result: The AAAAA is echoed back clearly audible with minimal clipping but very acceptable
Test 2
- Do: Open Linphone
- Do: Call echo test, (voip.ms is 4443)
- Do: Set android volume to between 1/2 and 3/4 with the hardware buttons
- Do: Wait for the recorded voice to finish spelling the instructions if any
- Do: Say AAAAAAAAA for as long as you can.
- Result: The AAAAAAAA is echoed back clearly audible for 2-3 seconds and then the volume (auditory) of the AAAAAAA becomes very low.
- Do: Stop saying AAAAAAAA.
- Do: Say AAAAAAAAA for as long as you can.
- Result: The AAAAAAAA is echoed back clearly audible for 2-3 seconds and then the volume (auditory) of the AAAAAAA becomes very low.
What should I do to fix the fluctuating volume?