Ear Ye! Ear Ye! Encore Convo Starters

Ears come in in many different shapes in animals. Who do you think has the best hearing, judging by their ear shape and size?
If we are crossing the street or in a busy place it is important to know which direction sounds are coming from for safety. Imagine a device that could help people who cannot hear know which direction sounds are coming from. How would they use it?
If you could have super robot-ears that could listen to tiny or far away sounds, what would you do with them?