Sometimes I hear a ringing sound in my ear, is it normal?

Not completely. These sounds in the head are generally called tinnitus and are very common. Tinnitus may occur from time to time or you may hear a sound constantly. It can be very thick or very thin, and you can hear it in one or both ears. When the ringtone is constant, it can make the person very uncomfortable. This discomfort can even go up to the extent that it affects the normal lives of people.

CAN OTHER PEOPLE HEAR THIS SOUND IN MY EAR?
This usually does not happen, but in some cases the listener may hear some sort of sound. This type of tinnitus is called objective tinnitus. It mostly develops either due to a vascular abnormality or due to the sounds that occur in the middle ear as a result of the contraction of the muscles.