8d0c15fd   
   XPost: sci.electronics.design   
   From: sylvia@not.here.invalid   
      
   On 20/01/2012 3:20 PM, RichD wrote:   
   > A noise canceling headphone consists of a headphone,   
   > plus an external microphone fed to an inverting input,   
   > right?   
   >   
   > Why does that cost $40 extra?   
   >   
   > --   
   > Rich   
      
   Does it? I think you probably mean that its price is $40 more than the   
   price of otherwise similar non-noise cancelling headphones.   
      
   Why is its price that much higher? Because the vendors think that that   
   price is the one that maximises their profit.   
      
   Sylvia.   
      
   --- SoupGate-Win32 v1.05   
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