This is the 10374th most frequent Japanese word.
鳴っ
"鳴っ" means "to ring" or "to sound."
鳴っています is the present progressive form of 鳴る, used to describe an action happening currently, indicating the phone's ringing sound.
電話が鳴っています。
The phone is ringing.
鳴っている is again the present progressive form of 鳴る, here representing the sound produced by the bell.
鐘が鳴っている音が聞こえる。
I can hear the sound of a bell ringing.
鳴いています combines 鳴く (to chirp, used for animal sounds) with the present progressive, describing the sound the bird is making as an ongoing action.