The overall goal of this research was to determine the feasibility of using sound to divert fish at electric power generating facilities. Consequently, the approach had to use a signal development process which could be customized to animals and site conditions at any plant location. We developed a new approach to using sound and obtained an avoidance response of traps by two species of upstream and downstream migrating salmonids which was 75 to 100% successful. Normal environmental stimuli like water temperature, sunrise, and sunset did not disrupt the response. This new patented approach is to use the sound frequencies and duration, amplitudes and patterns of sounds produced by a species of fish for the creation of the avoidance stimulus, on the basis of the hypothesis that sounds produced by fish are used for communication and, therefore, fall within the most sensitive range of hearing of that species. The avoidance responses observed are sufficiently high to suggest such sounds could be an effective and efficient means of guiding fish away from power plant intakes.