Transcript frequency
Test your hearing: http://www.ultrasonic-ringtones.com/ You can also try this test: http://journal.plasticmind.com/ears/mosquit o-tone-or-how-to-tell-youre-a-youngun/ Properties of Sound Pitch, along with loudness is another important property of sound Pitch is how high or low a sound is Pitch is determined by the frequency of a wave – As frequency increases, pitch increases – As frequency decreases, pitch decreases Wavelength Wavelength Wavelength and Frequency Short wavelength means more waves per second High frequency = High pitch sound Long wavelength means less waves per second Low frequency = Low pitch sound Frequency and Hertz Recall that the frequency of a wave is the number of waves occurring per second Frequency is measured in Hertz (Hz) One Hertz is equal to one wave per second For example, a frequency of 50 Hz means 50 vibrations per second A bass singer can produce frequencies lower than 80 Hz A trained soprano voice can produce frequencies higher than 1,000 Hz Pitch depends on Frequency: The bass singer below sings low notes, and the soprano singer on the right sings high notes. Frequency of high note: Frequency of low note: Human hearing range of frequency Most people can hear sounds with frequencies between 20 Hz and 20,000 Hz This range decreases as a person gets older Children can hear higher-frequency sounds than adults can Sound waves with frequencies above the human range of hearing are called ultrasonic waves Ultrasonic waves have frequencies over 20,000 Hz and have scientific uses Dogs can hear sounds with frequencies up to about 50,000 Hz Dolphins and bats can hear even higher frequencies, and use these high- frequency sound waves to communicate Sound waves with frequencies below the human range of hearing are called infrasonic waves Infrasonic waves have frequencies below 20 Hz cannot be heard but may feel like a rumble **Human 20-20,000 Pitch and Music Pitch is an important property of music because music uses specific pitches called notes To sing or play an instrument, you must change pitch often When you sing, you make your vocal chords vibrate by stretching and relaxing the muscles in your throat When your vocal chords stretch, they vibrate more quickly as air rushes through them This creates higher-frequency sound waves that have higher pitches When your vocal chords relax, lower-frequency sound waves with lower pitches are produced Instruments and Changing Pitch With musical instruments, you change pitch in different ways depending on the instrument For example, you can change the pitch of a guitar string by turning a knob to loosen or tighten the string A tighter guitar string produces a higher frequency, which you hear as a note with a higher pitch How else can you change pitch on an instrument? Range of Hearing Frequencies for Various Animals