Objectives : Intratympanic injection of corticosteroids membrane after noise-induced hearing loss is an accepted alternative to general administration. We investigated the effect on hearing of a hyaluronic acid gel with liposomes loaded with dexamethasone (DexP) administered into the middle ear. Methods : An acute acoustic trauma was performed to 13 guinea pigs for a period of 1 h on Day −2. Two 2 days after the noise trauma, the animals were then assigned randomly to four experimental groups: control without gel, gel injection, gel-containing free DexP, gel-containing DexP loaded into liposomes. Auditory thresholds were measured with Auditory Brainstem Response before Day −2 and at Day 0, Day 7 and Day 30 after noise trauma. Results : Seven days after, a complete hearing recovery was observed in the control group at all frequencies apart from 8 kHz, and no recovery was observed in the three groups receiving a gel injection. Thirty days after trauma, all of the animals had recovered normal hearing, apart from at the 8-kHz frequency, with similar auditory thresholds. Conclusions : Local DexP administration 48 h after a mild acoustic trauma did not improve hearing recovery, even with a sustained release in a specific gel formulation designed for inner ear therapy.