What is the minimum threshold of hearing in intensity level
     What is the minimum threshold of hearing in intensity level (decibels) for a tone at 2000 Hz? (Do not enter units)  What is the loudness of a 90 db tone at 2000 Hz? (Enter the answer in phons. Do not enter units.)  What is the intensity level required for a 2000 Hz tone to have a loudness of 85 phons? 
  
  Solution
a. minimum thershold of hearing 3
b. loudness of 90 db at 2000Hz is 95
c.intensity level for 2000Hz at 85 phons loudnes = 80 db

