no audio on samsung galaxy s5

i've got audio working on a samsung galaxy tab connecting to demo web app with chrome. but when i try to connect using samsung galaxy s5, i get no audio coming from phone. i can hear the audio from chrome so the phone is sending audio to chrome but the phone isn't playing back the audio from chrome.

looking through the logs, I see this:

com.ericsson.research.owr.examples.nativecall W/AudioRecord﹕ AUDIO_INPUT_FLAG_FAST denied by client

this warning doesn't appear on the tab.

i'm using nativecall on latest openwebwebrtc-examples with some modifications to get audio working.