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BELL SYSTEM TECHNICAL JOURNAL 



TABLE I 

 Classification of Range Controllers 



classification which tells what the device is designed to do. In this 

 system the numbers preceding the letters specify the input control 

 range in decibels, and the position of a horizontal bar indicates the 

 position of the main signal range with respect to the control range. 



The letters specify the time actions and in the case of vogads, where 

 several time actions may be combined, an arbitrary combination of 

 letters would be used. The final numbers specify the control ratio, and 

 in the case of vogads, where this might be different depending on 

 whether the input was increasing or decreasing, both values are given, 

 the former first. 



In this system, definitions of time actions are prerequisite and by 



way of illustration, the following symbols have been used: 



/ represents instantaneous, meaning very fast adjustment of device 



5 represents syllabic, meaning moderate speed adjustment of device 



V represents volume, meaning a combination of controllers which 



produces adjustment of device in response to dynamic speech 



so that the output volume is approximately determined by the 



input volume. 



Secondary Characteristics 

 In addition to their three primary characteristics, range controllers 

 may have a number of secondary features which are sometimes im- 

 portant. The outstanding ones are: 



/. Bias 



A neutral range controller is one which holds its setting during the 

 quiet periods between words and sentences and which changes its gain 



