Models play a crucial role in the development of our understanding of the auditory (or any other) system. They provide new insights from both a theoretical and practical point of view as well as providing a framework for summarizing existing knowledge. Most important of all, they provide predictions which can be tested experimentally. These experimental observations, in turn, will either serve to strengthen a specific model or, if theory and observation differ significantly, will provide new information leading to the development of improved models and hence an improved understanding of the processes being studied.

Serum immunoglobulin (IgG, IgA and IgM) levels were determined in patients with chronic tonsillitis before and one month after tonsillectomy. The preoperative levels of serum IgG, IgA and IgM were significantly higher when compared with the controls. The increase may be due to repeated antigenic stimulation. The post-operative levels for the three immunoglobulins were decreased; however, a significant reduction was observed for IgG only where the mean value was comparable with the control group. The data confirm that tonsillectomy does not disturb the humoral immune system of the body.

An auditory sensation follows generally as the result of the sequence stimulus, transduction, coding, transformation and sensation. This is then optionally followed by perception and a reaction. The stimulus is usually airborne sound causing movements of the tympanic membrane, the middle ear ossicles, the inner ear fluids and the basilar membrane. The movements of the basilar membrane are dependent on stimulus frequency: high frequency tones excite only the basal part of the cochlea, regardless of the stimulus intensity; low frequency tones at low levels only excite the so-called place specific region at the apical end but at high levels (above 60–70 dB SPL) cause appreciable movement of the entire basilar membrane. Basilar membrane tuning is as sharp as that of inner hair cells or auditory nerve fibers (Sellick et al., 1982) at least in the basal turn of animals that have a cochlea in physiologically impeccable condition.