True audio compression (dynamic range) and data compression are not the same. Only lossless data compression restores to complete form, mp3 the common audio data compression format is not lossless. The easy way to verify that no data has been lost in data compression or transmission is to do a checksum comparison, you can use md5 or sfv to compare the original file to the restored file, if the checksums are the same then no data has been lost, if they are different then the two files are not duplicates and some data has been lost or modified.