Yes, its in the cfgSFX section.
Small example:
class skylark
{
sounds[]={"sing1","sing2","sing3","sing4","sing5","sing6","sing7"};
name="$STR_CFG_SFX_SKYLARK";
sing1[]={"animals\skylark7",0.01,1,0.1,0.2,0.4,1};
sing2[]={"animals\skylark6",0.01,1,0.2,0.2,0.3,1};
sing3[]={"animals\skylark5",0.01,1,0.1,0.1,0.2,1.2};
sing4[]={"animals\skylark4",0.01,1,0.2,0.1,0.2,1.2};
sing5[]={"animals\skylark3",0.01,1,0.1,0.3,0.4,0.75};
sing6[]={"animals\skylark2",0.01,1,0.1,0.2,0.4,0.8};
sing7[]={"animals\skylark1",0.01,1,0.1,0.1,0.5,0.8};
empty[]={"","","","",1,5,40};
};
The sounds of course are in the Sound.pbo in .wav and .wss format
Planck