Psycho-biological Limitations

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Many psycho-biological limitations can be imposed on the auditory experience. We will look at several of them.

1. Biological position of the Ears effects Sound localization

Some authors have compared hearing with olfaction (smelling). If you block one of your ears with cotton, your ability to localize the position of sounds diminishes considerably. But if just one of your nostrils is stopped up when you have a cold, you could locate a rotten egg just as rapidly as if both your nasal chambers were operating unimpaired. One important physical (biological) difference between hearing and smell, then, is this: your ears are some 6 inches apart; your nasal chambers are separated by less than ½ inch. If you would like to demonstrate to yourself the importance of the "space between your ears" you might try a musical experiment. Find a hi-fi stereo with two moving speakers. Put the speakers as far as possible in the room. Now put on your favorite music and sit between the two speakers with your eyes closed. You will hear music coming at you from all directions. But some sounds will seem to be on right and others on your left. Now, put the two speakers right next to each other and repeat the experiment. Chances are, the music will seem compressed, pushed together, cut down in size to a point source. In short, the stereo music will sound monaural or "mono." Your ears are like the two speakers spread apart. Your nose and tongue are like the two speakers put close together. (McConnell, 1995)

Your ears can detect the location of sounds spread out in the left-right dimension rather well. But your ears do very poorly in locating sounds in the up-down dimension (Levine & Shefner, 1981, as cited in McConnell, 1995).

2. Frequency and Amplitude affect the pitch and loudness of the auditory experience

Sound waves have two important physical aspects: frequency and amplitude that affect our auditory experience. The frequency of a musical tone is related to how high or low the tone sounds to your ear. Put more precisely, the psychological pitch of a tone is primarily determined by the physical frequency of the sound wave. The amplitude of a musical tone is related to how loud or soft the tone sounds to you. Put more precisely, the subjective loudness of a tone is primarily determined by the objective amplitude ...