- Left ear catches sound from the left side and right ear catches sound from the right side more efficiently. Having two ears enables us to listen to sound coming from wide range of angle.
- When listening to a weak sound source, sounds arrived to two ears are summed up so that it can be listened more clearly.
- Sound localization ability is increased using two ears. Imagine stereo audio recordings. By just using two microphones when recording, the information where the sound came from is preserved pretty well.
- Our brains make use of two ears in order to selectively listen to what we want to listen (e.g. speech) and filter out unwanted sound.
In people suffering from SSD, these features are completely or partially unavailable. In fact, people with Single Sided Deafness have great difficulty listening to speech in noisy situations.