Are there any special audio settings needed to make Twilio VOIP on iOS work? -

i'm trying set twilio voip client on ios , have been able make of examples connect example server. when run in simulator or on device, i'm not able hear audio voip call. there special audio settings needed? i've tried:

uint32 route = kaudiosessionoverrideaudioroute_speaker; audiosessionsetproperty(kaudiosessionproperty_overrideaudioroute, sizeof(route), &route); 

but had no luck. i've set audio , voip uibackgroundmodes. there else should setting up?

are using twilio's trial account? if followed documentation , there still problems client voip calls, might worth shot upgrade. twilio has been having problems free trial accounts i'd try update first.