A sonogram is the image generated during ultrasonography, which is a diagnostic imaging technique that uses ultrasound to visualize anything inside the body. Ultrasound is sound with a frequency above the range audible to humans, about 20 kHz. In common parlance, both words are used to refer to the ultrasonography procedure.
edit What is Ultrasound and Sonogram?
Ultrasound is high frequency sound, inaudible to humans (approx. 20kHz).
When ultrasound waves are sent into the human body some of them bounce back when they hit tissues of differing density. The time it takes the reflected ultrasound waves to return to the machine is translated into an image of the internal organ, or of the fetus. This image is called an sonogram.
A sonogram is used by physicians to observe the growth of a fetus, to calculate their age and due date, and to see the presence of multiple fetuses. It is also used to diagnose internal problems such as pelvic bleeding, and to locate cancerous cells.
Ultrasound is used to produce a sonogram. It is also used in industry to measure the purity or uniformity of liquid, to measure the depth of water, and to search for underwater objects such as submarines. Whales and dolphins use ultrasound to communicate.
edit Uses of Ultrasound in Animal Kingdom
Basically humans are sight-centric species — i.e., we experience world mainly through the sense of sight. However some animals use ultrasound or sonar waves to sense their environment.
- Whales and Dolphins: Use ultrasonic sounds to capture their prey.
- Bats: As bats can detect frequencies between 100-200 kHz, they use the ultrasound technique to find their food.
- Insects: Many insects, like tiger moths, beetles, etc. have good ultrasonic hearing. They use this technique to escape being caught by bats.
- Dogs: Dogs can hear frequency in range 18-22kHz.
- Fishes: Several fishes like ray-finned fish can hear ultrasonic sounds.
- Frogs: Certain frogs like Amolops tormotus use ultrasound to communicate with other frogs.
- Grasshoppers and Mice: Grasshoppers and mice use ultrasound in making mating calls.