What can you hear but not see?

I show feelings without words and am often sent on a phone. What am I? Solve the riddle → I help you measure and draw straight lines. What am I? Solve the riddle → What has four legs in the morning, two in the afternoon, and three in the evening? Solve the riddle → What can be heavy but weigh nothing? Solve the riddle → I show roads, cities, and countries, but nothing on me is real. What am I? Solve the riddle →