Dictionary / Vocabulary / 音信不通
おんしんふつう · also いんしんふつう
break in contact; not hearing from; having no communication with
もし音信不通になったら警察に連絡してね。
If I drop out of contact, let the police know, OK?
4年以上も音信不通だったんだよ。
I haven't heard a word from them in over four years.