Category Sound

             Some of the most important applications of ultrasonics can be seen in the field of medicine. Ultrasonography or ultrasonic scanning is one of it, which uses high frequency sound waves to produce images of internal organs, vessels and tissues. This type of scanning is used to diagnose the condition of organs such as liver, kidneys or gallbladder.

            Then, there is something called obstetric ultrasound. It is a technique used during pregnancy to create images of a baby inside the womb.

 

       

 

 

    Another public health application of ultrasonics is in dental care. It enables the equipment called ‘descalers’ to remove plaque from teeth through a smoother and less painful experience.

            Yet another important use can be seen in the cleaning of equipment. What makes ultrasonic technology so popular in medicine is its effectiveness and affordability.

            Acoustic microscopy is a technology that helps in visualizing tiny structures using high frequency ultra sound waves. The microscopes in this fashion penetrate solid materials and create visible images of internal features, including defects like cracks and voids. For this purpose, they use frequencies up to several gigahertz.

             One of the most advanced types of acoustic microscopy is scanning acoustic microscopy. Here, the internal parts of a sample can be viewed without staining or causing any damage. It relies on a beam to scan the sample while it is in water.

            The difference between a traditional microscope and an acoustic microscope is that the former allows us to see only the surface of a specimen, while the latter obtains images from deeper layers. It also takes accurate measurements at a micro-level, which other microscopes may not be able to obtain.

          Just like humans, all forms of life in the Universe have the ability to hear, or sense things around them. But some of them have exceptional features for hearing, which enable them to survive better than others.

          One such animal is the elephant. Its hearing frequency is somewhere between 16 and 12,000 hertz, as a result of which, it can hear at a frequency 20 times lower than us.

          Another mammal that has a special auditory system is the fennec fox. It is a small species of fox seen in the sandy Sahara. It has large ears that play a vital role in hearing, as well as keeping the animal cool by spreading out during high temperatures. Other than these two, there are many animals that are sensitive to sounds. These include pigeons, owls, dolphins, etc. 

            As a matter of fact, no two species of animals look alike, or behave alike. Similarly, the abilities and senses of animals vary too, from species to species.

            One cannot expect a monkey to have the hearing ability of an elephant, nor can auditory ability between a marine mammal and a terrestrial animal be compared. Generally, it is seen that larger animals hear and use low frequency sounds, while smaller ones have with higher frequencies.

            However, there are always exceptions, as in the case of spade foot toads that can easily pick up low-frequency sounds. These are animals that live in desert habitats and spend their days buried in ground during dry seasons. They come out only when pools are formed after infrequent rains. And that is when their young ones are developed, before the water dries up.

            Similar to animals, birds and insects too have peculiar auditory features that help them adapt to surroundings.

 

          Kangaroo rats are unique animals that live in desert and dry, open areas. They are perfectly adapted to desert life, and can survive without drinking water, as they get moisture from their seed diet.

          But, what makes kangaroo rats special is their exceptional sense of hearing. It helps them detect enemies like owls and snakes, even when they are approaching from a distance.

          Kangaroo rats have large ear-drums and middle ears. However, the oval window between the middle and the inner ears is considerably smaller. This peculiarity helps the auditory system of the animal to magnify low frequency sounds by about 100 times.

          As a result, it can hear the sound of air flowing over the wings of an owl, or the scales of a snake moving across sand. Now, isn’t that a rare gift for an animal?

 

          The barn owl is a raptor that can be spotted on all continents except Antarctica. It is said to have extraordinary abilities that help in catching fast-running animals.

          The most predominant ability is the bird’s sense of hearing, which stands out for its sharpness. It is so superior that the bird can decipher the direction and height from which a sound comes! This is exactly what makes it a sharp hunter.

          Unlike others, the barn owl’s ability to hear is strengthened by its feathers. The heart-shaped facial disc made of stiff feathers helps the owl in picking up noise. It funnels any sound towards the ears, which open on either side of the bird’s head. The ruff of feathers is so important for this owl that without it, the bird cannot catch preys. And with it, even the slightest sound can be detected.

          Interestingly, a large portion of the barn owl’s brain is devoted to building sound maps of places!