You know what would be an interesting power for a story?
When, instead of just sensing emotions, a person "feels" the "vibrations" of the emotions when someone is speaking.
Say, for example, someone tells the person "go". The person would hear that, and in their mind, the word "go" will keep echoing, each time changing, depending on the emotion of the speaker. So, if the speaker was angry when they said "go", the person with the power may "hear" the word "go" getting louder, and angrier sounding. If the speaker had been sad, then the word "go" would get softer, and sadder.
It's a great way to limit the power of being able to sense emotions, if you don't want it to be too OP (over-powered)