[LAU] Alsa and 24-bit in Ubuntu Studio?

[Grekim Jennings]

I'm checking out Ubuntu Studio 12.04,  64-bit.  When I try to play a 
wave file with using aplay <name of file>,  I am told it is an 
unsupported format (and the file is identified correctly as 3 byte 
signed little endian mono) and it lists the available formats of little 
and big endian versions of 16 and 32 bit and 32 float, and even 8 bit.  
What happened to 24 bit?  Can I add it?  Thanks.