I don’t have a working SIM card right now so can’t try a call. Yes, I was running arecord in Ubuntu. My goal is to make the WP7611 like a USB handset for another computer, but I’m using Ubuntu for testing. Like I said before, we’ll use the WP7611 for LTE data, but I want to use the PCM codec for analog input and output. Is there a way I can play a .wav file on the WP7611 and make it seem like USB microphone data on Ubuntu?