The human audible range is the range of frequencies of sound that can be heard by the human ear. It extends from approximately 20 Hz to 20,000 Hz, although there is variation between individuals. The lower limit of the range is determined by the mechanical properties of the ear, while the upper limit is determined by the neural processing capabilities of the auditory system.
The human audible range is not uniform. The ear is most sensitive to sounds in the mid-frequency range, from about 2,000 to 5,000 Hz. This is because the ear's frequency response is shaped by the resonance of the middle ear bones (the malleus, incus, and stapes). These bones amplify sounds in the mid-frequency range and attenuate sounds at higher and lower frequencies.
The human audible range is also affected by age. As people get older, they tend to lose hearing in the high-frequency range. This is due to a number of factors, including damage to the hair cells in the inner ear and changes in the neural processing of sound.
Animal Audible Ranges
The audible ranges of animals vary greatly. Some animals, such as bats, can hear sounds up to 100,000 Hz, while others, such as elephants, can only hear sounds down to about 20 Hz. The audible range of a particular animal is determined by a number of factors, including the size of the ear, the shape of the ear canal, and the neural processing capabilities of the auditory system.
Infrasound and Ultrasound
Infrasound is sound below the human audible range, while ultrasound is sound above the human audible range. Infrasound can be produced by a variety of sources, including earthquakes, volcanoes, and wind turbines. Ultrasound can be produced by a variety of sources, including bats, dolphins, and medical imaging devices.
Although humans cannot hear infrasound and ultrasound, these sounds can have a variety of effects on the body. Infrasound can cause nausea, dizziness, and anxiety, while ultrasound can damage the ears and other tissues.