In some species such as the bullfrog the eyes and tympani are much the same size .
The bullfrog is the size of the tympanum indicates the sex of the frog ; males have tympani that are larger than their eyes while in females .
In some species such as the bullfrog , the size of the tympanum indicates the sex of the frog ; males have tympani that are larger than their eyes while in females , the eyes and tympani are much the same size .