Suppose that the sound level of a conversation is initially at an angry 71 db and then drops to a soothing 54 db. assuming that the frequency of the sound is 504 hz, determine the (a) initial and (b) final sound intensities and the (c) initial and (d) final sound wave amplitudes. assume the speed of sound is 343 m/s and the air density is 1.21 kg/m3.