The inner ear is a receptor that transmits messages to the brain about the location of sound and does so through the use of the following: (1) pitch;

(2) loudness;

(3) timbre;

(4) spatial localization; and (5) Duration. (Lecture 2, p.4)

The shape of the inner ear in addition to any sounds that mask the tones being processed by the ear for instance in how white noise masks a 2 kHz tone. (Lecture 4, p.18) in addition, psychoacoustics measures the head and spatial localization or the head in relation to the surrounding in which the tones or sound is heard in relation to the position of the head. The cues for location of pure tones are reported as:

(1) Interaural time differences (it'd); and (2) Interaural level differences (ILD). (Lecture 10, p.2)

ILD result from sound bending around an object known as diffraction. ILD locate low frequencies, can be detected over the entire frequency range, and are large enough to make provision of clues on localization generally in high frequencies. The ear pinna and the head are complex and directly dependent upon one another for reception of incoming stimuli "from every direction in space." (Lecture 10, p.24) Behavioral psychologists relied on self-report in tasks that were "yes-no' to find sensory thresholds for:

(1) detection of weight;

(2) brightness or light;

(3) color saturation;

(4) discrimination of frequency;

(5) loudness;

(6) touch or toughness;

(7) touch in terms of pressure;

(8) taste (sweet, salty, bitter, sour) and (9) smells. (Lecture 2, p. 5)

It is now known that neural activity is a chain reaction occurring...

(Lecture 2, p. 26) When the human head moves the sound arrives differently at the two ears although the sound image does not change. This involves combining the information about the head's position with the information concerning the location of the sound. Vision assists in defining the head's position in space however; it is possible to locate sound with eyes closed. (Lecture 10, p.10) When vision changes although auditory system is normal it is possible to make adjustments to this on the part of human beings and even of young owls. Tonotopically arranged audio cues are combined in mammals in the inferior colliculcus to create a map of space. (Lecture 10, p.35)
Summary and Conclusion

The field of psychoacoustics is an exciting field because it is multidimensional field of study and of practice, which makes it a very large field for study, and practice. That which has been learned in this course will be applied variously by those in this field. However, as many experiential variables exist in this field it is likely that this field will experience growth and expansion in the years to come.