PSYB51H3 Chapter 9-15: Chp-9-15
Document Summary
Vibrations of an object cause its surrounding medium to vibrate as well and this vibration in turn causes pressure changes in the medium. Sound waves travel at a particular speed depending on medium, moving faster thru denser substances: sound travels faster in water than in air. Basic qualities of sound waves: frequency and amplitude. Amplitude or intensity: the magnitude of displacement of a sound pressure wave. Frequency: for sound, the number of times per second that a pattern of pressure change repeats. Hertz (hz): a unit of measure for frequency. Loudness: the psychological aspect of sound related to perceived intensity (amplitude) Pitch: the psychological aspect of sound related mainly to perceived frequency. Low-frequency sounds correspond to low pitches and high-frequency sounds correspond to high pitches. Humans can detect sounds that vary from about 20 to 20,000 hz. Elephants hear vibrations at very low frequencies that help detect presence of large animals.
