Psychology 3041/6014 Spring, 2014 1 of 6 FUNDAMENTAL AUDITORY FUNCTIONS 1. Loudness - Physical attribute of sound is intensity - Perceptual attribute is loudness a) Sones - Unit of measure used to describe subjective loudness of sounds of differing intensity - 1 sone = loudness of 1000 Hz tone at 40 dB SPL - From graph (s349) we see # of sones (perceived loudness) doubles every 10 dB of intensity - Compare +6 dB intensity means doubling intensity, and +10 dB intensity means ~tripling intensity) - So as you triple intensity, you only double the perceived loudness b) Frequency dependence of loudness - Due to the mechanics of the basilar membrane, the arrangement and number of hair cells, and the auditory pathway (including cortical areas) perception of loudness differs for sounds of different frequencies - Can see this in threshold plotsPsychology 3041/6014 Spring, 2014 2 of 6 c) Equal-loudness contoursPsychology 3041/6014 Spring, 2014 3 of 6 2. Pitch a) Discrimination (JND) b) Mel scale c) Intensity affects pitch i. For low tones ii. For high tonesPsychology 3041/6014 Spring, 2014 4 of 6 3. Multiple frequencies stimulation a) Beats b) Masking - Asymmetry of frequency effects in masking - Simultaneous masking - Forward masking - Backward masking - “Line busy” hypothesis How common is it to hear two sounds very close in frequency, in the real world?Psychology 3041/6014 Spring, 2014 5 of 6 4. Threshold shifts a) Auditory fatigue b) Threshold shift i. Temporary ii. Permanent c) AdaptationPsychology 3041/6014 Spring, 2014 6 of 6 5. Warning tones and masking a) Consider frequency of the masking (background) noise b) Make each component of the warning ~15 dB above background at that frequency c) Use multiple frequencies d) Each component, and total sound, not to exceed danger
View Full Document
Unlocking...