Test 3 Flashcards
What is a phon? What does it measure
Phon is a unit of loudness level and a perception of intensity. It is 1K at 50 dBSPL = 50 Ph; follows dB scale at level 1K; 1000 Hz reference tone is the tone the others are matched to. Comes from going up the scale of 1000 Hz presented at 50 dBSPL.
What is a sone? What does it measure?
Sone is a unit of a 1000 Hz tone presented at 40 dBSPL. Since SPL in dB and loudness level is phons are equivalent at 1000 Hz- we may also define 1 sone as the loudness corresponding to a loudness level of 40 phons.
What are Beats or also know as best Beats?
A beat is when they help close the gap to figure out where it is heard. 2 tones only a few frequencies apart cause an in phase / out of phase pattern and a beat. If 2 tones are equal in level and the frequency begins to close between the two tones the beats become louder and slower. As the 2 tones widen the beats become faster until 2 separate tones are heard.
How are Beats used?
Reisz found for optimal DL’s, a modulation of 3 beats/sec. He then adjusted the amplitude of one of the two tones (beating) until the beats became minimally audible. The intensity differences between the two tones were taken as the measure of the DL.
Ways to test beats.
Modulation; remember beat is intensity modulated (needs 2 tones) and warble is the frequency modulated.
what are warble tones? what do they help measure?
a little bit above and below the frequency. where you can pick up the difference. they help measure frequency difference.
What is spectral splatter?
10 msec or less result in transients that spread energy. side band of energy. (Static sound)
what are the minimal audible curves? where is the human ear most sensitive?
human hearing is most sensitive between about 2000 and 5000 Hz. (Played the different frequencies)
what is the method of limits?
The stimulus is under the experimenter’s control.and the subject simple responds after each presentation. The process is repeated until the subject no longer perceives the sound, at which point the series is terminated. (descending run)
example of the method of limits
suppose we are interested in the absolute sensitivity (threshold) for a particular sound. 1. the sound is presented at a level expected to be well about threshold (level we can hear 50% of the time). 2. since it is clearly audible- the subject responds by stating that he heard the sound. 3. the level of the sound is then decreased by a discrete amount (say 2 or 5 dB) and present again.
Steps of method of limits
-Step size (dB increment)
-Too large a step size to reduce accuracy because the actual threshold may lie anywhere between 2 discrete stimulus levels (ex: 10 dB vs 2 dB)
-A smaller step size permits a more precise estimate but also may be more tedious and may have a few “wasted” presentations due to test levels well above or below the threshold.
what is the method adjustment?
-the experiment is in control
-the adjustment method differs in 2 ways:
1. the stimulus is controlled by the subject instead of by the experimenter.
2. the level of the stimulus is varied continuously rather than in discrete steps.
what is response proclivity?
it is a human bias, the reaction (McDonald’s toy gone wrong)
what is the method of constant stimuli?
- random
- the method of constant stimuli involves the presentation of various stimulus levels to the subject in random order. unlike the other 2 methods, the method is a nonsequential procedure. in other words, the stimuli are not presented in an ascending or descending manner. a range of intensities is selected, which based upon previous experience or a pilot experiment, encompasses the threshold level.
what is a Mel? what does is measure?
measure pitch compared to frequency. looks at the difference. it is what happens if you change the intensity of the sound. ex: if you increase it increases (perception). difference of lineman needs to be small. need to be able to tell the difference. the smaller the better.
