Fig. 3. Frequencies and sound pressures of constant-frequency (CF) jamming sounds in relation to the audiogram of big brown bats. (A) Full frequency range. (B) Expanded frequency range used for jamming experiments. At frequencies of 18–32 kHz, the jamming stimuli have a constant sensation level of about 65 dB. Filled symbols indicate CF jamming stimuli; other symbols indicate individual animals. [Replotted from Dalland (Dalland, 1965) and Koay et al. (Koay et al., 1997).]