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In the course of previous investigations, Dix, Hallpike, and Hood have concluded that the phenomenon of loudness recruitment is attributable to disordered function resulting from injury or disease of the hair cells of Corti's organ.In the present paper, an account is given of an experimental study of certain loudness changes caused by adaptation of the hair cell responses to pure tone stimulation.Two outstanding characteristics of the adapted state are defined: “on‐effect normality” and “relapse.” Both resemble very closely those described by Matthews in the case of adaptation occurring the muscle stretch receptors of the frog.Further studies in a number of human subjects show that both of these characteristics are exhibited regularly by the unadapted hair cell responses of individuals suffering from degenerative changes of the hair cells.These studies appear to establish a very close similarity between “on‐effect normality” occurring in the case of the adapted normal sense organ and the phenomenon of lou...

(1961). The Effect Upon Vestibular Function in the Cat of Unilateral Destruction of the Nucleus Fastigii. Acta Oto-Laryngologica: Vol. 53, No. sup159, pp. 94-100.

(1957). A Study of the Clinical Features and Pathological Changes within the Temporal Bones, Brain Stem and Cerebellum of An Early Case of Positional Nystagmus of the So-Called Benign Paroxysmal Type. Acta Oto-Laryngologica: Vol. 48, No. 1-2, pp. 89-105.

A simple stereotaxic apparatus is described for drilling orientation holes in the temporal bones of the human cadaver.Its use, in conjunction with a simplification of the wax plate method of reconstruction, makes possible the rapid reconstruction from a single temporal bone of the saccular and utricular maculae in their correct angular relationships to the classical skull planes.The procedure can be combined with routine examination of the histological structure of the maculae.A description is given of the application of the equipment, of the method of reconstruction, and of the technique of measurement of the angular relationships of the macular planes.The results are described and compared with those reported earlier by de Burlet.

A case is described of fatal air embolism resulting from tympanic inflation carried out through the external auditory meatus for the treatment of secretory otitis media. The post-mortem findings, including the result of a histological examination of the temporal bone, provide evidence that the air left the tympanum through one or more small natural defects in the tegmen-tympani and passed forwards outside the dura to the region of the foramen lacerum medium. Here it caused surgical emphysema of the peri-carotid connective tissue and entered the venous system by rupturing the thin-walled venous sinuses which are present at this point. Thereafter the air passed by way of the cavernous and petrosal sinuses to the right side of the heart and so caused death.

1. The loudness recruitment angle is defined. It is found to provide a useful quantitative index of the recruitment phenomenon.2. The results are described of a study of the angle based upon 200 cases of unilateral deafness due to Meniere's disease. The magnitude of the angle is found to vary linearly and within close limits, with the amount of the deafness.3. The recruitment angle shows some dependence upon the frequency characteristic of the deafness, being greater with low than with high frequency types of hearing loss.4. The results of a comparative study of two small selected groups of subjects, with and without severe symptoms, suggest that the recruitment angle tends to be increased during the active phases of the disease.5. The results are discussed in the light of recent work on the electromechanical behaviour of the cochlea, and an explanation is suggested of the neurological mechanism of the loudness recruitment phenomenon based upon the dual excitation theory of Hallowell Davis.

By means of a photocell, light source and interrupter, it has been found possible to produce phase-reversals in a musical tone of approximately sinusoidal waveform. When this tone is caused to fall on the human ear, phase-change beats are heard as has previously been described. When this tone is caused to fall on the ear of a decerebrate cat, and its auditory-tract responses are recorded by means of a cathode-ray oscillograph, a temporary and marked decrease in amplitude of the response occurs, corresponding to each phase-change. This decrease in amplitude corresponds to the phase-change beat which is heard by the human subject and is postulated on the resonance theory of hearing. When the cochlear (Wever-Bray) response of the cat is similarly recorded, the response exhibits no such fall in amplitude in correspondence with the phase-change, which is moreover reproduced with marked fidelity. The cochlear response must therefore originate in some non-resonant structure.

Schuknecht and his co-workers have shown that partial lesions of the cochlear nerve in cats may be associated with normal hearing at threshold for pure tones. Comparable findings are described in two human subjects.