The effectiveness of an acoustic barrier to deter the movement of silver carp, Hypophthalmichthys molitrix, and bighead carp, H. noblis, was evaluated. A pond (10 m, x 5 m x 1.2 m) was divided in half by a concrete-block barrier with a channel (1 m across) allowing fish access to each side. Underwater speakers were placed on each side of the barrier opening and an outboard motor noise (broadband sound; 0.06 – 10 kHz) was broadcast to repel carp that approached within 1 m of the channel. Broadband sound was effective at reducing the number of successful crossings in schools of silver carp, bighead carp and a combined school. Repulsion rates were 82.5% (silver carp), 93.7% (bighead carp) and 90.5% (combined). This study demonstrates that broadband sound is effective in deterring carp and could be used as a barrier in an integrated pest management system.