A coyote can locate a sound source with good accuracy by comparing the arrival times of a sound wave at its two ears. Suppose a coyote is listening to a bird whistling at \(1000 \mathrm{~Hz}\). The bird is \(3.0 \mathrm{~m}\) away, directly in front of the coyote's right ear. The coyote's ears are \(15 \mathrm{~cm}\) apart.

a. What is the difference in the arrival time of the sound at the left ear and the right ear?

b. What is the ratio of this time difference to the period of the sound wave?