To start, that may be what the horn is supposed to sound like. All horns are not the same.
Download it again and check the file sizes, they should match exactly.
Or if you are proficient in software fiddling, load each into a hex editor and compare the checksums, they should also match.
The Checksum is a far more precise test than file size, but file size will show a problem if you are displaying all the digits, not X.XM (Megabytes) or X.XK (Kilobytes)
Note, I just noticed, In Win 7 I can't seem to adjust the Size reading to give all digits like the old Ver....
Thus this may not help but then again it may as the readout for all my sound files is in whole Kbytes.