huh. your cell network must be pretty bad.

i recall only one time where whatsapp voice was ok-ish (better then regular cellphone) quality but the lag totally killed the conversation. when someone calls me via xy-voice i usually deny it and call them back via cell. it became a meme that only cheapos do this some time ago.

international might be different as quality and lag issues are more prevalent and money is usually what keeps the conversation short.