Synonyms for Jarring:

adj.

brassy (adjective)
strident, piercing.
cacophonous (adjective)
inharmonious, unmusical, raucous, dissonant, discordant.
discordant (adjective)
clashing, disharmonious, unmusical, cacophonous, differing, conflicting, inharmonious, unmelodious, quarrelsome, dissonant, discord, discordant, hostile, unharmonious, antagonistic, loud, tuneless, fricative, contentious.
jarring (adjective)
wobbly, jumpy, unharmonious, bouncy, grating, bumpy, rough, uneven, shaking, loud, harsh, jerky, rocky, staggering, agitating, unsettling, shrill, rasping, clashing.
rough (adjective)
bumpy.
shrill (adjective)
cutting, Caterwauling, reedy, ear-piercing, jangling, squeaky, treble, squealing, rasping, grating, screaming, creaky, strident, hoarse, acute, shrieking, scratching, harsh, scraping, penetrating, whining, raucous, whistling, screeching, piercing, high-pitched, shrill.
uncontrolled (adjective)
jerky.

n.

uncoordinated, convulsive, ungainly, clumsy, heavy, awkward, be all fingers and thumbs, wooden, robotic. taboo, raspy, dry, squawky, outrageous, indecent, scandalous, sounds, scratchy, horrifying, appalling, horrific, horrendous. brittle, monotonous, tinny, brassy. concussion (noun)
jolting.
jarring (noun)
rough, jolting, jolty, unsmooth, bumpy, cacophonous, cacophonic.
jolting (noun)
wobbly, rocky, steady, smooth, jumpy, jerky, uneven, staggering, firm, unsettling, bouncy.

v.

agitating (verb)
upsetting, Flustering, jolting, shaking, quivering, agitating, twitching, disquieting, stirring, palpitating, troubling, quaking, perturbing, shuddering, churning, quavering, shivering.
displeasing (verb)
irritating, Scandalizing, shocking, Angering, disturbing, annoying, disappointing, displeasing, Aggrieving, disgusting, provoking, Bothering, offending, Riling, repelling.
jar (verb)
discord.

Other synonyms:

raspy, squawky, scratchy. tinny. brittle. dry. Other relevant words:
wobbly, jolty, jumpy, unsmooth, cacophonic, jerky, clashing, loud, unsettling, dry, rough, rocky, bouncy, brassy, staggering, raspy, bumpy, scratchy, uneven, squawky.