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telephone art, and the results of these investigations are serving to 

 guide us not only in the development of telephone instruments but in 

 all developments of telephone transmission. The Laboratories' 

 scientific and design work has contributed in large measure to the 

 improvement of methods of recording and reproducing sound in the 

 phonograph and sound-picture arts. The art of radio broadcasting 

 owes a large debt to the work of the Laboratories, not only for the 

 fundamental scientific knowledge contributed but also for actual 

 instrumentalities employed. To those with impaired hearing, the 

 Laboratories' investigations have made possible improved means for 

 determining the extent of their impairment, and improved hearing 

 aids. Finally, at least in America, we are becoming what I may term 

 as "noise conscious." In our cities, noise is being recognized as a 

 factor affecting comfort, efficiency, and possibly even health. The 

 development of accurate methods for the measurement of noise is 

 contributing to studies looking towards the reduction of noise. 



Lecturer's Note: The lecturer wishes to acknowledge assistance given 

 in the preparation of this material, particularly by Dr. Harvey Fletcher 

 and Mr. W. H. Martin of the Bell Telephone Laboratories' staff. 



