The difference between audible and inaudible sounds is their frequency ranges; it is relative to the ability of the human ear to only perceive as audible those sounds that fall within a frequency range between 20 and 20,000 hertz. Other organisms, such as insects, dolphins, dogs and bats, are capable of perceiving sounds that are outside of the frequency range that is audible to humans. Certain species of insects, for example, are capable of perceiving sounds that are four times as high as the upper sound frequency limit of human hearing.Know More
What is perceived as sound is a mechanical wave, or vibration, with the properties of displacement and pressure. Unlike electromagnetic waves, sound waves require a medium to travel through and can not propagate through a vacuum. Solids, liquids and gases all carry sound waves, although the physical properties of a substance affect the speed at which they travel.
What is commonly referred to as "sound" is actually the perception of the kinetic energy of sound waves by the brain. The human auditory organs are unable to react to sound waves above or below what is termed the audible range, which represents sound waves with wavelengths falling within the lower frequency range of about 55.75 feet, and at the upper frequency limit, about two-thirds of an inch. The higher-frequency sounds above the audible limit are referred to as ultrasound.Learn more about Optics & Waves
Sound is generally classed as ultrasonic when its frequency exceeds 20,000 hertz. This is the upper range of humans' ability to perceive, though the ultrasonic range of frequencies extends upward into the millions of hertz.Full Answer >
Although there are many reasons sound is important; a couple reasons are that it allows humans and animals to hear and communicate, and it is a primary component in the functioning of sonar equipment. Sound occurs in a variety of waves, which have different characteristics and produce different types of noises.Full Answer >
Humans can generally hear frequencies from 20 to 20,000 hertz. However, under ideal laboratory conditions, humans have been able to hear frequencies as low as 12 hertz. As humans get older or are exposed to loud sounds that damage their hearing, the highest frequency they can hear decreases.Full Answer >
When sound waves strike a surface, they reflect off of that surface and can return to the source of the sound as an echo. To a listener, this may be identical to the original sound, just delayed and possibly distorted by its path through the air. If the echo arrives quickly enough, it may seem to be part of the original sound, forming a reverberation instead of an echo.Full Answer >