Sound Waves and Amplitude

Sound Waves

• Sound waves are characterized by their wavelengths, amplitudes, and other parameters.
• The pitch of a sound refers to the perception of frequency, with high-pitched notes having a high frequency and low-pitched notes having a low frequency.

Amplitude in Sound Waves

• Amplitude is a measure of how far particles oscillate back and forth in a longitudinal wave, such as sound.
• In a high-energy wave, the amplitude is large, because the particles oscillate over a large distance.
• In a low-energy wave, the amplitude is small, because the oscillations are small in size.

Intensity and Volume

• Intensity is measured in units of energy over the area and time, and is detected as the loudness of a sound.
• The decibel scale is a logarithmic scale used to measure the intensity of sound waves.
• Volume is the perception of loudness from the intensity of a sound wave, and is proportional to the amplitude of the sound wave.

Frequency in Sound Waves

• Frequency is the number of wave cycles passing by every second, measured in Hertz (Hz).
• A sound wave with a frequency of 262 Hz has 262 wave cycles passing by every second.
• A plot of pressure over time can be used to visualize the periods between successive compressions of a sound wave.

Pitch and the Acoustic Range

• The acoustic range represents the sounds that humans can hear, from 20 Hz to 20,000 Hz.
• Sounds above 20,000 Hz are considered ultrasound, while sounds below 20 Hz are considered infrasound.
• Humans can typically hear sounds as low as 20 Hz and as high as 20,000 Hz.
• Musical pitches can be put in order from high to low frequency, with high-pitched notes having a high frequency and low-pitched notes having a low frequency.