While visiting the Grand Canyons, you couldn’t honestly tell me that you didn’t scream into the canyon just to hear your echo come back to you. Don’t be ashamed, we all do it. Many kinds of animals actually use their echo to find out where they are in a closed area or to find out if there are any other animals close by. One classic example is the bat.
To understand what an echo is, you first have to understand what sound is. In Webster’s Fourth Edition College Dictionary, sound is “vibrations in air, water, etc. that stimulate the auditory nerves and produce the sensation of hearing.” Vibrations through the air can be thought of as oscillation of molecules. As the molecules oscillate, they pass energy on to surrounding molecules, and those molecules pass energy on to other surrounding molecules. This is how sound travels, and the oscillation of the molecules is often referred to as sound waves.
An echo happens when the sound waves reach a surface, bounce off of it and travel in the opposite direction. For optimum echoes, the surface should be perpendicular to the waves, and as frictionless as possible. In places like the Grand Canyons, you can hear many echoes because the sound waves bounce off of surfaces, then others bounce off of other surfaces, and some will bounce back to you, but at different times.
In echolocation, bats send out short pulses that have a high frequency. The short pulses that the bats send out have such a high frequency that the average human cannot hear them. The waves that the bats send ripple out from them circularly and will bounce off of anything that is in the bat’s way, and will also go back to the bat in the form of an echo. By instinctively examining the echoes that they receive, the bats will be able to tell the direction that the object is coming or going from, how fast it is going that way and how far away it is from the bat. Some bats can even tell how big the object is that is in their way. If bats didn’t have the use of echolocation, they’d need some other way to stay alive, because echolocation is the bat’s way of life. It is the primary reason that it is able to live in its environment.
In severe times such as the six miners missing by the Cave in at the Crandall Canyon coal mine in Utah, sound is an effective way to know the existence of the miners.
They are also know as mouse-eared bats. The little brown bats being one of the most common bat species in most of the United States and Canada have many interesting and unique characteristics that set them far apart from other animals. Unfortunately, with a disease called white-nose syndrome bat populations have been on the decline. With the species being threatened it is even more important to fully understand the little brown bat and all of its habits and characteristics.
If you put your finger gently on a loudspeaker you will feel it vibrate - if it is playing a low note loudly you can see it moving. When it moves forwards, it compresses the air next to it, which raises its pressure. Some of this air flows outwards, compressing the next layer of air. The disturbance in the air spreads out as a travelling sound wave. Ultimately this sound wave causes a very tiny vibration in your eardrum - but that's another story.
waves were reflected back to the transducer as they crossed interfaces of different acoustic impedance. More simply, the ultrasound bounced off the
Once believed to be no more than random utterances made involuntarily, scientists now know that these sounds are a part of a complex linguistic system that primates make deliberately. In order to make sense of these sounds, primatologists first cataloged a group’s vocal repertoire before determining the circumstances under which those sounds were made. While primate voices are distinct, individuals produce comparable calls within types. However, simply ascertaining the context does not necessarily prove its purpose. To achieve a greater understanding, researchers recorded different calls and then, using speakers, played where a group could hear and studied the various responses (Larsen,
Ultrasound is sound waves that have a frequency above human audible. (Ultrasound Physics and Instrument 111). With a shorter wavelength than audible sound, these waves can be directed into a narrow beam that is used in imaging soft tissues. As with audible sound waves, ultrasound waves must have a medium in which to travel and are subject to interference. In addition, much like light rays, they can be reflected, refracted, and focused.
Sound is a type of longitudinal wave that originates as the vibration of a medium (such as a person’s vocal cords or a guitar string) and travels through gases, liquids, and elastic solids as variations of pressure and density. The loudness of a sound perceived by the ear depends on the amplitude of the sound wave and is measured in decibel, while its pitch depends on it frequency measured in hertz, (Shipman-Wilson-Higgins, 2013).
Ultrasounds use the same concepts that allow sonar on boats to see the bottom of the o...
In Frankenstein and The Bride of Frankenstein, sound is used as an effect to scare people and create a “spooky” feeling. They used the sounds of a storm with rain and thunder, the sound of footsteps coming up from behind people, and other noises like creaky stairs, floors, and doors. This created that “haunted” or “spooky” feeling that would be used over and over again in horror films for decades. When they used sound effects, it was to emphasize that something was either happening or about to happen.
As said above, both light and sound waves have to do with interference. In sound, interference affects both the loudness and amplitude. When two waves’ crests overlap, the amplitude increases. The same is true with the troughs of the waves, which decrease the amplitude.
In 1977 Irene Pepperberg, a recent graduate of Harvard University, did something very bold. At a time when animals still were considered automatons, she set out to find what was on another creature’s mind by talking to it. She brought a one-year-old African gray parrot she named Alex into her lab to teach him to reproduce the sounds of the English language. “I thought if he learned to communicate, I could ask him questions about how he sees the world.”
Another way some ants can communicate with one another is by sound.
Acoustics is a science that deals with the study of sound. It is known to be one of the branches of physics; studying oscillations and sound waves from the lowest to high frequencies. Acoustics is known to be one of the oldest sciences, and dates back to ancient times as people had the need to understand the nature of speech and hearing. The main reason acoustics was discovered and is one of the oldest sciences is because of the need for the knowledge of the sounds of music and musical instruments. Pythagoras, an ancient mathematician, was the first person to ever find out that tone height corresponds to the length of the sting or tube. While Aristotle, Pythagoras apprentice at the time, helped more to explain that an echo is created as the sound reflection from obstacles.