The hair cells in the ear are sensory receptors.
The ear hair and ear hair cells help you hear as they help detect the sound waves.
So ear hair is very important for your hearing.
You could hear some without the ear hair in your ears but having the ear hair helps you hear much better.
The ear hair basically works as nerve receptors for hearing.
The cochlea is filled with two fluids (endolymph and perilymph), and inside the cochlea is the sensory receptor, the Organ of Corti, which contains hair cells, or the nerve receptors for hearing.
So while ear hair can seem annoying and not important the ear hair does have an importance to it.