Impairing rhymes with:
comparing, comparing, despairing, pairing, paring, preparing, repairing, sparing, unsparing, airing, baring, bearing, behring, bering, blaring, caring, chairing, comparing, daring, declaring, derring, despairing, erring, fehring, flaring, garing, gehring, glaring, haring, herring, maring, mehring, nehring, overbearing, pairing, paring, preparing, red-herring, repairing, scaring, sharing, snaring, sparing, squaring, staring, swearing, tearing, uncaring, unsparing, wareing, waring, wearing, zaring, zehring, zeringue
Impairing sounds like:
imprimis, inference, inferences, inferring, informing, informix, informs, infringe, infringes, invariance, inverness