Why is my ringer volume automatically decreasing?

[shakercs]

Ringer volume automatically decreasing

Ringer volume automatically decreasing , every time I call anyone I'll must increase the ringtone volume cause I can here him .
Samung Note 2 Android 4.4.2

 

[B. Diddy]

Welcome to Android Central! Sorry, are you talking about ringtone volume or in-call volume?