Chapter 9: What is Sound?

Hertz

(Hz) - units of frequency 1 Hz = 1 cycle/second

Decibel

(dB) - units of amplitude (sound pressure) logarithmic ratio between given sound and "reference" sound (very faint)

What are the physical qualities of sound waves?

amplitude and frequency

What is the timbre caused by?

caused by harmonics and other high frequencies that are also produced by many single vibrating sources

What are sound waves a combination of?

individual frequency sine waves

What are the psychological qualities of sound waves?

loudness and pitch

How does frequency correspond to pitch?

low-frequency sounds correspond to low pitches high-frequency sounds correspond to high pitches

Fundamental Frequency

lowest-frequency component of a complex sound

Amplitude

or intensity - the size of a sound wave

Loudness

psychological aspect of sound related to perceived intensity or amplitude

Pitch

psychological aspect of sound related to the fundamental frequency

Timbre

psychological difference in sensation/quality caused by different complex sounds that have the same loudness and (fundamental frequency) pitch

Pure Tone

sound containing just one frequency pure sine waves that are not common in the real world

Frequency

times/second the sound wave oscillates

Harmonic Spectrum

way to describe or characterize common form of complex sound typically caused by a single vibrating source

Greater amplitude of movement results in...

the amplitude doubled, frequency remains the same

Greater frequency of movement results in...

the amplitude remains the same, frequency is doubled