In ~/init.d for each host a specific rc file exists that will be called from the rc script
The script uses the name returned by the 'hostname' command, prependen with 'rc.'. E.g. if your raspberry's hostname is 'myraspberry', the script should be named 'rc.myraspberry'.
If you use ALSA/Portaudio using an external USB sound card or dongle, put these lines in /etc/asound.conf: