Loudness and Pitch Flashcards
What is Loudness
Loudness is a subjective perceptual psychoacoustic correlation to the objective measurable physical quantity “ intensity”
Describe the Phon Scale
Loudness Level: Using equal loudness contours, the phon scale determines dB SPL levels of different tones that are perceived as equally loud. Compares loudness of other frequencies to loudness of 1000 Hz tone.
Describe the Sone Scale
Relative loudness: compares the relative loudness of different sounds. This in this scale a sound that is 5 sones is perceived as being louder than 1 sone sound.
What is a typical task procedure for the Sone Scale
Typical Task Procedure: Measured basically the same way that phons are measured, except comparison is relative:
◼ Start with an index tone (e.g., 1000 Hz at 40 dB)
◼ Then present a different tone
◼ Now adjust different tone until it’s twice as loud (not
equally loud) as the index tone
◼ Now adjust it until it’s half as loud
◼ Repeat over hearing range
Describe the Mel scale
-Used to measure pitch
-As with loudness, subjects are asked to compare a tone against a reference tone
1000 Hz is the reference tone (again)
1000 mels = 1000 Hz tone at 40 dB SPL
500 mels is a tone half as high in pitch as the reference tone
2000 mels is twice as high
How do intensity changes affect pitch
-Greater intensity tone stimulates more of the Basilar Membrane
-Larger amplitude of traveling wave = more area activated/stimulated
Why do frequencies some louder or quieter depending on frequency
-Point of maximal stimulation shifted toward nearer end of BM (and away from area of maximum sensitivity) as intensity goes up
-Opposite is true when sensitivity goes down
What is complex pitch
There are multiple frequencies played once
Affected by numerous factors such as strongest component frequency, pattern of frequencies present, and where in the range of human audibility the frequency changes occur
