Impact rhymes with:
packed, pact, repacked, unpacked, abstract, act, attacked, attract, backed, blacked, bracht, counterattacked, cracked, detract, diffract, distract, enact, exact, extract, fact, hacked, inexact, intact, interact, jacked, kracht, lacked, medfact, overreact, packed, pact, pracht, protract, racked, react, redact, reenact, repacked, retract, sacked, schacht, slacked, smacked, snacked, stacked, subtract, tacked, tact, tracht, tracked, tract, transact, unpacked, whacked, wracked
Impact sounds like:
impacted, impastato, impeached, imposed, infect, infected, infest, infested, infused, invest, invested, invoked