Recent experiments on sensory systems in tropical coral reef fishes have suggested other ways in which fishes can be affected by ocean acidification. Simulations with near-future levels of carbon dioxide (800 µatm) have shown olfactory cue disruption for orange clownfish larvae. Furthermore, sight and hearing are also affected by increased carbon dioxide concentrations in the ocean. An experiment conducted on juvenile ambon damselfish in which a possible predator was introduced into their habitat in a watertight plastic bag showed that the damselfish were less wary of the predatory threat at higher CO2 concentrations. Another experiment conducted on clownfish examined hearing responsiveness under heightened CO2 concentrations. When reef noises were played from one side of an aquarium under current CO2 levels, the clownfish generally avoided that side. However, under higher CO2 conditions, the clownfish would congregate closer to the reef noises. These experiments suggest that ocean acidification affects brain functioning in reef fishes.