The glitching sound in question is the sound that 173 makes when he opens doors. I'm guessing he was trying to open a door that couldn't be opened or something.
Yeah I think that is the noise 173 makes when he's trying to open a Keycard-Door but fails. It's odd, it didn't make that kind of glitched noise before.
Some of those sounds are made from SCP-173 when he moves, but it does sound like the sound file got stuck in a glitch, possibly due to the scp getting a little stuck and shifting rapidly