a bit like DTMF phone-tones or modem
log sweep down , with reversed steps.
Remix of Freesound #234239 by zagi2 ... http://www.freesound.org/people/zagi2/sounds/234239/ now with spatial [sic] effects. Sounds much better when downloaded.
Audacity's dirty stretch-tempo applied to Freeound #233554 by oceanictrancer.
variant of Freesound #233314  Sounds acoustic but is entirely synthesised.
a little bit of freesound #233275 by vladj http://www.freesound.org/people/vladj/sounds/233275/ looped and processed.
Only a little different from the original by foolboymedia ... http://www.freesound.org/people/FoolBoyMedia/sounds/222066/ This remix has more bass , hint of flanger ...
(overly?) glitched remix of bit of foolboymedia's "80s-vibe.wav" http://www.freesound.org/people/FoolBoyMedia/sounds/231257/ This remix is loopable , (and sounds better when downloaded).
Remix of Freesound 232849 by jimimod ... http://www.freesound.org/people/JimiMod/sounds/232849/ Remix is mostly processing in DTBLKFX a free VST circa 2008 [Windows ...
see title. [sounds different when downloaded ]
remix of Freesound #138101 by snakebarney, a flash-charging whine-sound
Synthesised robot heart noise , a bit like an electric bass guitar , there's a few usable ones in there
Attempt to remove noise from freesound #13570 by acclivity ... http://www.freesound.org/people/acclivity/sounds/13570/ The noise reduction is a request ... http://www.freesound.org/forum/sample-requests/34914/74002
realistic , but synthesised metal clang with (too?) long reverb
like computer noise when a peripheral device plugged-in or unplugged it's #5 & #6 from here ... http://www.freesound.org/people/Timbre/sounds/232209/