I once made an Y7 additional pack with 5-gear transmission and sound made from an original sound file. It was, however, not very good, and does not (apart from idling) sound like the original at all. At least it does not sound like the KIHA..
You are welcome to try the sounds. I have a bad old original recording which I used for this purpose.
You can find the sounds among the files on address
http://rail.lyckhem.net/PV040618 (the wav files).
The original recording is several minutes, and covers the run between Hultsfred and Silverdalen in 1980, and is recorded with a very cheap cassette recorder, put on the motor hood.
Jolin