PHYSICAL CHARACTERISTICS OF AUDITION 



61 



spends to stimuli in conversation of lesser energy content, such as 

 the minor shadings and fainter consonant sounds. While it is physi- 

 cally possible to produce an amplification of speech so that this region 

 is raised into the diminished area it is impracticable to do so because 

 of the pain which would be caused by the louder components. A 

 diminution in sensation area can, therefore, be only partially com- 

 pensated for. In case the area is extremely narrow a deaf set fur- 

 nishing optimum volume can only serve as an aid to lip reading. 



7. Quality of Hearing. The sensation of a normal ear at any point 

 in the auditory sense range (Fig. 1) may be described by a number of 

 different adjectives, such for example as "clear," "musical," "even," 



Fig. 3 



QUALITY AREAS -LEFT EAR (CHK) 



"sustained," "smooth," "pure," etc. Such a description may, in 

 fact, be taken as a reasonable indication that the quality of sensation 

 at the point in question is normal. Abnormal ears sometimes ex- 

 perience a subjective degeneration of quality of pure stimuli which 

 they describe as "rough," "harsh," "sharp," "buzzing," "vibrating," 

 "hissing," etc. This subjective degeneration is independent of any 

 tinnitus or head noises which the patient may have. Fig. 3 shows 

 various regions of the sensation area which are degenerated in the 

 case of CHK, left ear. The shaded area was not explored. The 

 boundaries of the degenerated regions are usually more sharply 

 marked than the outer boundaries of the sensation area. The sensa- 

 tions in these areas are so radically different from the sensation of a 



