javax.sound.sampled.LineUnavailableException : Why am I getting this exception?

What could be the reason for this ?

javax.sound.sampled.LineUnavailableException: line with format 
  PCM_SIGNED 44100.0 Hz, 
  24 bit, 
  stereo, 
  6 bytes/frame, 
  little-endian not supported.

I don't know about the rest, but most PCs I've encountered use 8 or 16 bit 'bit depth' while that uses 24 bits. It indicates a very finely nuanced recording quality. If 8 bit is 'phone quality' and 16 bit is 'CD quality', then 24 bit would be 'master recording quality'.