AUDIO PERCEPTION

By: Emily Beck and Cheyenne Corbine

What does it mean?

Audio perception is the way we understand and receive sound.

(The ear is a non-linear device: what is received isn't always what you will hear)

Auditory Perception The Fletcher-Munson equal-loudness

contour curves: indicate the ears average sensitivity to different frequencies at various levels [dB vsHz]

Phons: a unit for measuring the apparent loudness of a sound equal to the intensity in decibels of sound having a frequency of 100 cycles/second. When a group listens the sounds have equal loudness

The Fletcher-Munson equal-loudness contour lines

Beats Beats are an effect made by two

tones that differ only slightly in frequency and have approximately the same amplitude.

This is commonly used in tuning instruments. The beats slow down as you get closer to the correct pitch or where the two match.

Combination tones Combination tones result when two

loud tones differ by more than 50 Hz.

Sum tone- f1+f2Difference tone- f1-f2Ex= 1600+500=21001600-500=1100 These formulas are used to

compute the fundamental tones.

Masking Masking is the phenomenon by which

loud signals prevent the ear from hearing softer sounds.

Masking is greatest when the frequency of the sound and the frequency of the masking noise are close to each other. For example 8k-Hz tone will mask a 7.5k-Hz tone ad it will become softer. A 1000 Hz tone wont have as much of an effect.

9 hours of white noise http://www.youtube.com/watch?v=Y5_cOOkUGGM Tinnitus masking: you have ringing in your ears so

they use white noise to mask it out and prevent the ear from ringing. It works because the frequencies are close to each other and they have a similar timbre. The ringing and the white noise together cancels the ring. (Used for sleep)

With instruments when there two with a similar timbre and one is louder it can change or completely cancel the other instrument. That is why musicians in the studio and live have to focus on their choices of microphones and instruments and where they are placed