present, i.e. the patient states that he can hear better in a noisy place such
as a railway carriage or motor-car. Various explanations have been put
forward to account for paracusis, the most probable being that patients
suffering from Otosclerosis, and consequently unable to hear lower tones,
obtain more advantages than normal people from the raising of their friends*
voices in a noisy place, as they (otosclerotics) are not distracted by the low-
pitched hum of machinery to the same extent as people with perfect hearing.
Fig. 194. Horizontal section through anterior
margin of oval window of fetus. 1, Footplate
of stapes; 2, Fibrous tissue joining endosteum
of vestibule toŚ3, Remains of fetal cartilage
in bony capsule of cochlea; 4, Basal coil of
cochlea; 5, Saccule.
Fig. 195. Normal joint between footplate o
stapes and margin of oval window.
Fig. 196. Otosclerosis, wifh ankylosis of footplate of stapes to anterior margin of oval window. 1,
Otosclerotics speak in a low, well-modulated voice, very different from the
loud, harsh speech of an advanced case of nerve deafness. Giddiness is a
rare symptom, but may be present in varying degree even to the extent of
true paroxysmal vertigo.
EXAMINATION. In Otosclerosis the tympanic membrane is usually normal.
In about 10 per cent of cases a flamingo-pink blush (Plate X, 20), may be seen