replace Audio.Play with?, best way to do ambient

I just heard about this last week, really
a hidden gem, I did a tut on item pickup
noises here

sites.google.com/site/terrymorgan1213/tutorials/master_audio_get_start

I read the manual about replacing audiosource with master audio page 47
'Then you are free to import Master Audio and
start doing sound design, first configuring the sounds that the tool removed.'

 It found 31 in the hierarchy, almost all
enemies with this aisetc.cs, there's
a 'hurt' and and an 'attack' sound

I use locate32 (free) to find text in
files.

if(hurtVoice && GetComponent<StatusC>().health >= 1){
audio.clip = hurtVoice;
audio.Play();

My question is, what's the master audio
version of audio.Play?



3 more-
I also have a looping ambient sound on
my player, nature sounds, etc. Is there a
better way to do this? I'd like variations
on it.

Suppose I have a waterfall, animated machine, etc, I want to play a sound for,
how to do this in Master Audio?


Do sounds loaded as a Resource have to
be in Assets/Resource folder?