These are sound effects that were created by Skywalker Sound. They were most likely created by Gary Rydstrom, and debuted in F/X2 (1991). It is a series of sound effects consisting of loud "DING!" impact sounds in varying pitches. Links: https://soundeffects.fandom.com/wiki/SKYWALKER,_METAL_-_TRANSFORMER_CLANGING#Audio_Samples