In the present study, effects of underwater sound transmission on growth, feed utilization and behavior of Koi fish (Cyprinus carpio, initial weight 3.67 +/- 0.18 g) was investigated via exposure to Urban Noise, Silk Road, Sufi Ney, and a Quran performance. Underwater sound transmissions were performed daily with playbacks between 08:00-08.30, 12:30-13:00, and 17:00-17:30 hours, throughout the feeding trial for a period of 90 days in a recirculating aquaculture system. An experimental group without any sound served as control. Results showed that musical stimuli tested in this study positively influenced fish growth and feed efficiency. Experimental fish presented slow growth performance during the first period however the disturbed swimming behavior of fish scattering in the tanks changed to a more regular swimming and improved growth thereafter, an indication of lower stress condition or acclimatization of fish to sounds. As a result, fish growths and feed efficiencies were influenced by musical stimuli with remarkably higher rates in the Quran performance and instrumental Sufi Ney treatments, compared to the Silk Road or the control group. Urban noise presented adverse effect on fish growth and feed efficiency. Hence, musical stimuli could be considered as a growth promoting factor ensuring fish welfare in intensive aquaculture facilities.