For professional audiology advice, please contact your local clinic for a consultation. Blog Human Hearing Range. Hearing Health. The Human Hearing Range. Jun, 30, It went something like this: "Remember when you were in school and they'd do those hearing tests? Try the audio checks below and find out. What is the normal human hearing range?
Test your hearing with our Online Hearing Test Take our free online test. How does noise travel to your ears? What is the difference between hertz and decibels? Did you know?
What are the frequencies humans can hear? Sounds below 20 Hz are called infrasound , whereas those above 20, Hz are ultrasound. Neither is perceived by the ear, although infrasound can sometimes be felt as vibrations. When we do hear low-frequency vibrations, such as the sounds of a diving board, we hear the individual vibrations only because there are higher-frequency sounds in each.
Other animals have hearing ranges different from that of humans. Dogs can hear sounds as high as 30, Hz, whereas bats and dolphins can hear up to ,Hz sounds. You may have noticed that dogs respond to the sound of a dog whistle which produces sound out of the range of human hearing. Elephants are known to respond to frequencies below 20 Hz.
The perception of frequency is called pitch. Most of us have excellent relative pitch, which means that we can tell whether one sound has a different frequency from another.
Typically, we can discriminate between two sounds if their frequencies differ by 0. For example, Pitch perception is directly related to frequency and is not greatly affected by other physical quantities such as intensity. Musical notes are particular sounds that can be produced by most instruments and in Western music have particular names. Combinations of notes constitute music.
Some people can identify musical notes, such as A-sharp, C, or E-flat, just by listening to them. This uncommon ability is called perfect pitch. The ear is remarkably sensitive to low-intensity sounds. Sounds as much as 10 12 more intense can be briefly tolerated.
Very few measuring devices are capable of observations over a range of a trillion. The perception of intensity is called loudness. At a given frequency, it is possible to discern differences of about 1 dB, and a change of 3 dB is easily noticed. But loudness is not related to intensity alone. Frequency has a major effect on how loud a sound seems. The ear has its maximum sensitivity to frequencies in the range of to Hz, so that sounds in this range are perceived as being louder than, say, those at or 10, Hz, even when they all have the same intensity.
Sounds near the high- and low-frequency extremes of the hearing range seem even less loud, because the ear is even less sensitive at those frequencies. Table 1 gives the dependence of certain human hearing perceptions on physical quantities.
When a violin plays middle C, there is no mistaking it for a piano playing the same note. The reason is that each instrument produces a distinctive set of frequencies and intensities. We call our perception of these combinations of frequencies and intensities tone quality, or more commonly the timbre of the sound.
It is more difficult to correlate timbre perception to physical quantities than it is for loudness or pitch perception. Timbre is more subjective. Terms such as dull, brilliant, warm, cold, pure, and rich are employed to describe the timbre of a sound.
So the consideration of timbre takes us into the realm of perceptual psychology, where higher-level processes in the brain are dominant. This is true for other perceptions of sound, such as music and noise. We shall not delve further into them; rather, we will concentrate on the question of loudness perception.
A unit called a phon is used to express loudness numerically. Phons differ from decibels because the phon is a unit of loudness perception, whereas the decibel is a unit of physical intensity. Figure 2 shows the relationship of loudness to intensity or intensity level and frequency for persons with normal hearing. The curved lines are equal-loudness curves. Each curve is labeled with its loudness in phons.
Any sound along a given curve will be perceived as equally loud by the average person. The curves were determined by having large numbers of people compare the loudness of sounds at different frequencies and sound intensity levels. At a frequency of Hz, phons are taken to be numerically equal to decibels.
The following example helps illustrate how to use the graph:. Figure 2. The relationship of loudness in phons to intensity level in decibels and intensity in watts per meter squared for persons with normal hearing.
The curved lines are equal-loudness curves—all sounds on a given curve are perceived as equally loud. Phons and decibels are defined to be the same at Hz. The graph in Figure 2 should be referenced in order to solve this example. To find the loudness of a given sound, you must know its frequency and intensity level and locate that point on the square grid, then interpolate between loudness curves to get the loudness in phons.
To find the intensity level of a sound, you must have its frequency and loudness. Once that point is located, the intensity level can be determined from the vertical axis. Follow the phon curve until it reaches Hz. At that point, it is below the 70 dB line at about 67 dB. Locate the point for a Hz and 60 dB sound. Find the loudness: This point lies just slightly above the phon curve, and so its loudness is 51 phons. Look for the phon level is at Hz: 63 dB. These answers, like all information extracted from Figure 2, have uncertainties of several phons or several decibels, partly due to difficulties in interpolation, but mostly related to uncertainties in the equal-loudness curves.
Further examination of the graph in Figure 2 reveals some interesting facts about human hearing. First, sounds below the 0-phon curve are not perceived by most people. So, for example, a 60 Hz sound at 40 dB is inaudible. The 0-phon curve represents the threshold of normal hearing. We can hear some sounds at intensity levels below 0 dB. For example, a 3-dB, Hz sound is audible, because it lies above the 0-phon curve.
The loudness curves all have dips in them between about and Hz. These dips mean the ear is most sensitive to frequencies in that range. Which of the following is correct about sound? Large amplitude - Loud sound II. High frequency - Low pitch. Which of the following happens due to atmospheric refraction? Twinkling of stars II. Advanced sunrise and delayed sunset. Which of the following is responsible for the production of an echo? Which of the following is an example of electromagnetic waves?
Microwaves are electromagnetic waves having frequencies in range of. An oscilloscope is an instrument which allows us to see waves produced by. When the Sun is near the horizon during the morning or evening, it appears reddish. The phenomenon that is responsible for this observation is.
More Physics Questions Q1. In a convex lens, when the object is placed at infinity, where is the image formed? In which of the following cases the apparent weight of a body in an elevator becomes zero? The inability of a body to change its state of rest or uniform motion by itself is known as :.
0コメント