What type of scans are used these days to monitor the growth of developing baby in the uterus of the mother?

What is the name of passage in outer ear which carries sound waves to the ear-drum?

Why should we not put a pin or pencil in our ears?

How is an ultrasound scan for fetus (unborn baby) better than aX-ray?

What is the name if the device which is used to find the depth of sea (or ocean) by using ultrasonic sound waves?