You can click the different options in the image below to access to their explainations directly.

PSound configuration window
DirectSound output device
Here you select the sound device for playback.
The various functions that uses direct CD-ROM access (Scan CD-ROM, Add audio CD tracks) will use the specified CD-ROM drive.
Loop count
Specifies the number of times the sound will loop. If it is 0, the sound will play once and stop. If PSound does not detect a loop point, the sound will never loop.
If checked, the sound will loop infinitely. This parameter is ignored when you convert the sound.
F.O. time
Specifies the duration, in seconds, of the fade out. Fade out only occurs if the playing sound contains a loop point. When the end of the sound is reached, after it has been looped [Loop count] times, the sound will fade out during [F.O. time] seconds. If the end of the sound is reached before the fade out finishes, the sound will loop again. Of course, by setting the fade out time to zero, you disable it.
Force to ... Hz
If checked, PSound will play sounds at the specified sample rate, in hertz. When a sound doesn't contain sample rate information, PSound will play it at the default 22050 Hz frequency. This feature is useful if the frequency is not correct. For instance, if the sound is played too fast, you can force PSound to play it at 11025 Hz, if the sound is played too slow, you can try to set this parameter to 44100 Hz.
It does not resample the audio data.
Autostart conversion
If checked, PSound automatically starts the conversion (you don't have to press the Start button). Ignored in batch conversion.
Autoclose conversion dialog box
If checked, PSound automatically closes the conversion dialog box when the conversion is finished (you don't have to press the Close button). Ignored in batch conversion.
Do not delete output file on stop
If not checked, PSound deletes the output file when you stop the conversion. If you check this option, PSound leaves the file. You can check it if for example you just want the beginning of a sound.
See the Convert page for informations about the conversion process.
Clear playlist at open/scan
If checked, PSound will clear automatically the playlist when you open or scan a file (or if you start a CD-ROM scan).
Always show the current entry
If checked, PSound automatically scrolls the playlist so that the current entry will be always visible when the window is resized or when the current entry changes (Next/Previous).
Fix Need For Speed 2-3 music
You must enable it to play correctly music of the games Need For Speed 2 and 3. It might also be useful for other EA games.
Playlist Font
Displays a window letting you select the font to use for the playlist.
Autostart scanning
If checked, PSound automatically starts the scan (you don't have to press the Start button). Ignored in directory scans.
Autoclose scan dialog box
If checked, PSound automatically closes the scan dialog box when the scan operation is finished (you don't have to press the Close button). Ignored in directory scans.
Scan dropped files
If checked, PSound automatically scans the files dropped from the Explorer to the main window. Otherwise, it tries to open them.
Never ask to scan invalid files
If not checked, when you open a file, and that file is not recognized, PSound will ask you if you want to scan the file. If the option is checked, PSound does nothing if the file is invalid.
Exclude file extension
If checked, when an entry is to be added during the scan process, PSound will remove the file extension from the entry name.
Fast mode
In "fast mode", PSound scans files... faster. However, it can sometimes miss data. For those who would like to have a more precise description, in fast mode PSound scans files "dwordwise" (or "4-bytewise"), else it scans files "bytewise". (Does not apply to the Scan CD-ROM command). Not really recommended...
Stop scanning on read failure (cd-rom)
This option alters the behavior of the Scan CD-ROM command when an error occurs. If PSound fails to read a sector of the CD-ROM (generally because it's damaged), it will continue with the following sectors if this option is off. If it's on, it will stop the scan.
Extract Metal Gear Solid dialog text
This option is specific to Metal Gear Solid (MGS), the first. Does not work for MGS2 or 3. If it's checked and you're scanning a MGS1 file, PSound will set the entry name to the first phrase of the speech, if avaible. It will also try to convert special characters from certain language. I've the French version, so French special characters (which are not French-exclusive in fact) are displayed correctly. I also tried to support Japanese, but it's really broken (actually, kanjis do not have a fixed value, so...). Because of this problem, you may prefer to disable the option. See also the Metal Gear Solid page.
Cut XA data when silence detected
This option is only used by the "Scan CD-ROM" command. So when you're scanning a CD-ROM, and XA audio data is encountered, PSound will separate the track in numerous sound clips whenever it detects silence. Added mainly for "Tales of Phantasia", but could be useful for other games...?
See the Scan page for informations about scanning.
Closes the configuration dialog box, and applies the changes.
Closes the configuration dialog box, without applying the changes.

PSound settings are stored in PSound.cfg, so if you delete this file, you'll get the default settings, as if you were running PSound for the first time.