We currently do not support 24 bit or 32 bit WAV files.
You could try using the Import Wizard in Binary Data Type mode.
On the Header Bytes page, select everything in the right preview window from the word "RIFF" to four bytes after the word "data" then click Next. Set the data Type to Integer, the Size to 3 and the Count to 1 and click Finish. Depending on who created the file, it may be 24 bits stored on a 32 bit boundary so you might also try setting Size to 4.
There will probably be chunks at the end that you will have to delete.