Good question and I hope I can answer correctly and in a way that is understandable.
The Audya uses a number of files essential for its operation, the tests make sure these files are in good condition. This is done by comparing the current data with known correct data. If the two results match there is a high probability the integrity of the file is good, if there is a difference, then some corruption has occurred and it is necessary to replace the corrupted file with a known good one.
If the file is corrupt there is a good chance there will be some problems as a result. The symptoms will vary depending on the affected file.