WhatsApp calls chopped

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 4.1
HARDWARE (XA2, X10, X10 II, …): XA2
UI LANGUAGE: German
REGRESSION: (compared to previous public release: Yes, No, ?): Happens since V4.0

DESCRIPTION:

When calling via WhatsApp, I hear the other caller chopped. With 4.0 this was only within the first minute, but in the meantime this happens throughout every call and all the time, so it has become very naggy.

PRECONDITIONS:

STEPS TO REPRODUCE:

  1. Call OR be called through WhatsApp

EXPECTED RESULT:

Clean audio call through Internet

ACTUAL RESULT:

Chopped audio

ADDITIONAL INFORMATION:

(Please ALWAYS attach relevant data such as logs, screenshots, etc…)