580 BELL SYSTEM TECHNICAL JOURNAL 



four feet long were used as the experimental guides. At one end of 

 these guides were launched waves having frequencies of roughly 150 

 megacycles. The lengths of the standing waves so produced gave the 

 velocity of propagation. Other experiments utilizing a probe made up 

 of short pickup wires attached to a crystal detector and meter enabled 

 the configuration of the lines of force in the wave front to be determined. 

 This was done for each of four types of waves. For certain types the 

 properties had already been predicted mathematically. For others 

 the properties were determined experimentally in advance of analysis. 

 In both cases analysis and experiment proved to be in good agreement. 



The Dependence of Hearing Impairment on Sound Intensity.^ John 

 C. Steinberg and Mark B. Gardner. This paper discusses the 

 measurement of hearing loss for levels of sound that were well above 

 the deafened threshold and hence were audible to the deafened person. 

 In the tests, observers having unilateral deafness, i.e., one impaired 

 and one normal ear, balanced a tone heard with the deafened ear 

 against the tone heard with the normal ear. For some persons, the 

 impaired ear heard less well than the normal ear for all sound levels. 

 For others, tones which were well above the deafened threshold were 

 heard about equally well with either ear. In other words, such deaf- 

 ened ears tended to hear loud sounds with normal loudness. It was 

 found that this type of deafness could be represented quantitatively 

 on the assumption that it was due to nerve atrophy. Loudness 

 judgments for a normal ear in the presence of noise were found to be 

 similar to judgments by a nerve deafened ear. Relations, based on 

 the loudness properties of normal ears, have been extended to represent 

 the loudness heard by deafened ears. 



^ Jour. Acous. Soc. Amer., July 1937. 



