When you visit the clinic for an ultrasound in London, you might find yourself wondering exactly how those pictures of your baby appear on the screen. While the technology that is used is state of the art, the concept of ultrasound is actually fairly easy to understand, and as the name suggests, it is based on high-pitched sound waves.
We can hear a wide range of sounds, but there are some that are too high or too low for human ears to detect. This is why there are some whistles that a dog can hear, but we cannot. The probe that is placed against your stomach during your ultrasound in London sends out ultrasound waves that are even higher pitched than this. We can’t hear them, and neither can the baby who is being scanned, even though he or she will start to recognise the sound of your voice before being born. The waves can be focused on a particular part of you or the baby, or even on your baby’s heart to see how well it is beating.
The high-pitched ultrasound waves the probe produces can be used to create a picture of your baby in much the same way that a bat uses echolocation to “see” the world. Although we aren’t usually very good at recognising objects from the sounds that bounce off them, you have probably noticed that sounds change depending on your environment. Your voice might echo back loudly when you are walking under a bridge, or produce hardly any echo at all while you are passing through a leafy park.
The equipment used during your ultrasound in London can tell a lot more about the objects that a sound wave has encountered than we can. The high-frequency sound waves that it sends out bounce off different parts of your baby, creating echoes that come back and are picked up again by the probe. The ultrasound equipment can take these echoes and turn them into detailed pictures of your baby. You get to see what the ultrasound equipment has heard.