AVR files are associated with Audio Visual Research software application. What kind of data do AVR files hold? Files with AVR extension store audio tracks. The format was popular among Atari ST users for which platform the Audio Visual Research software was available.
After converting the file to the new format, you will be able to use other programs to support it. Keep in mind, however, that the ULAW file after converting to AVR may differ slightly from the original. The most important information should be kept, but if you want the file after conversion from ULAW to AVR to be the same, you have to do this carefully and choose the proper application from the list below.
There is no guarantee, of course, that the conversion will come up to all your expectations, but it will certainly help you. If, after all, the effect of converting ULAW to AVR does not meet your expectations, you can simply try to find on the Internet a different version of your file in ULAW format, properly converted to a AVR file by someone else. If this fails, use the information provided in the further part of the website.
Unfortunately, if after performing the two previously described steps (trying to find your ULAW file converted by someone else, and the attempt to convert it to AVR on your own) you still have a problem with your file, then there are only a few solutions left. You can once again try to find and install an application that can open the ULAW file in its original format (without conversion to AVR file). Such a solution will be difficult to implement, but it certainly will give the best result.