PhaseSeeker:
I really don't see why you need the same code that is present in every Arduino IDE, but here you are:
I don't see any code in that program to change the modem to the voice-receive mode.
38400 baud can be marginal for SoftwareSerial. This is probably a task that would be more suited to an Arduino with at least two HardwareSerial ports - such as Mega, Leonardo or Micro.
...R