Interpreting auditory stimuli and triggering the appropriate physical responses are key biological processes through which individuals navigate their environment. A wide variety of acoustic frequencies are presented by the environment, and the relationship between frequencies can characterize complex hearing, and in part, predict responses to specific types of auditory stimuli. Due to the physics of sound waves, sound vibrations occur not only at the fundamental frequency (n) of that sound, but also double that frequency, or the first harmonic (2n). Perception across a variety of frequencies, as well as this idea of harmonics, we can more effectively test nuanced aspects of zebrafish hearing and interpretation. Since zebrafish use auditory hair cells for audition, characterizing their capacity for complex hearing will better relate them to mammalian and other higher order auditory models. Using habituation to measure non-associative learning, and prepulse inhibition to measure acoustic precision and sensitivity, assays normally designed to observe startle response modulation can now be used to evaluate pitch perception and interpretation. This study measures the baseline responsiveness for a variety of frequencies, and we hypothesize that if harmonics are interpreted as more similar than unrelated tones, habituation to a fundamental frequency (n), will accelerate the rate of habituation to a harmonic frequency (2n) more than to a frequency unrelated to the fundamental. Using high-speed recording at millisecond resolution and FLOTE tracking software, we analyzed the responses of five dpf zebrafish larvae. Frequencies of 200-2000Hz were used to test baseline response levels, as well as harmonic relationships (ie 200Hz vs 400Hz). Future studies could use the acoustic environment of an organism to rationalize aspects of complex hearing, including sounds that might indicate danger or predators. In addition, this study suggests a characterization of complex hearing that can be applied across species and animal models.