caused by its production, to locate her new mate. Female choice for complex calls can be explained by the tuning of the túngara frog’s inner ear organs: the amphibian papilla and the basilar papilla. The frequency that the basilar papilla is most sensitive to is 2130 Hz, and the chuck’s dominant frequency is about 2500 Hz. The smaller the frequency difference between the male’s chuck frequency and the tuning of the basilar papilla, the greater the neural excitation of the female. Thus, females prefer the lower frequency chucks that are closer to the tuning frequency of the basilar papilla. Female choice for low frequency chucks comes from female’s preference for larger males providing reproductive benefit. The size difference between the mates determines the fertilization rate in that decrease in the size difference leads to decrease in the number of unfertilized eggs and increase in fertilization rate. Due to the tendency of female túngara being larger than male túngara frogs, larger males lessen the size gap with females and benefit the fertilization. And since larger males have larger larynxes, they produce lower frequency of sound (chuck and whine). Consequently, strong sexual dimorphism can be observed in larynx size. Until about 16 mm snout-to-vent length, females and males have larynges of about the same size. However, above this point, males show strong positive allometric growth in larynx size until the plateau of growth at about 24 mm snout-to-vent length, around the time of the male’s first call in the field. This shows that male reproductive behavior is triggered at the full development of the larynx. Female choice for conspecific whine comes from the lack of prediction between phylogenetic similarity of the túngara frog species and acoustic similarity of their calls. Also, shared common ancestry is suggested to lead to shared auditory and neural responses. Compared to the former female choice, female choice for conspecific whine has less significance due to the lack of overlap between the habitat of túngara frogs and the habitat of other Physalaemus species, decreasing the instances of avoiding the calls of close relatives. The phonotaxis experiment endorses the female call preference for complex calls and low frequency chucks. In terms of female choice for complex calls, the experiment is set up in a way that a female is placed equidistant between two speakers broadcasting series of test calls. The results show that females predominantly prefer a whine with