To send a prerecorded sound file to the active connection window, use the Connection/Send Sound File... menu item or drag the sound file icon from the File Manager and drop it in any connection window or icon, whether active or not.
Sound files can be in Windows .WAV format, monaural or stereophonic, 8 or 16 bits per sample, at 8000, 11025, 22050, or 44100 samples per second (if you're making a file expressly to be sent by Speak Freely, for best sound quality and efficiency select 8000 16 bit monaural samples per second). For compatibility with Unix and the World-Wide Web, you can also send files in Sun Audio File or raw Sun Audio formats (.AU files). Such files are assumed to be recorded at 8000 8 bit monaural samples per second, using mu-law encoding.