So there are two different issues here.
First, there are OEM sound files, usually based on an ESU commercial file, that may have specific settings the manufacturer wants as the default settings. This was the case with Atlas' S-2 file, for example, where they originally wanted the sound to come on when the engine was powered up ("Not F8" in ESU-speak, meaning the sound is on if F8, which normally turns the sound ON, is off). Intermountain had ditch lights configured in a certain way if I remember correctly. Usually, these files are available from the manufacturer, but some are available from the ESU web site. For example, here is the link to the list of the ESU North American/Australian factory-equipped sound files for the LokSound 5:
https://projects.esu.eu/projectoverviews/19 The second issue is that there are folks who customize their own sound files using the LokProgrammer software. The stuff you can do with sound customization if you know what you are doing is almost limitless. Have a recording of that special Milwaukee Road bell you heard as a teenager? By all means, sub it in a sound file for the regular bell. Change the whistle or horn; change the actual logic controlling the whistle or horn. Etc. But the learning curve is very steep. You will find some of these customizations on the LokSound Groups.io list, under the files section (you'll have to join the LokSound group in Groups.io to access the files), but I don't know of any central repository of whole customized sound files for the LokSound.
I've found that the standard ESU files do everything I want them to do, so I've never gone down the customization road. But if you DO want to go down that road, you can probably spend the next several years playing around with this.
John C.