Male Rana catesbeiana bullfrogs are known for their loud mating call. The call is emitted not by the frog's mouth but by its eardrums, which lie on the surface of the head. And, surprisingly, the sound has nothing to do with the frog's inflated throat. If the emitted sound has a frequency of 295 Hertz and a sound level of 90 dB (near the eardrum), evaluate the amplitude of the eardrum oscillation? The air density is 1.21 kg/m3.