title: Maximum frequency of any mobile phone speaker
body: <p>I want to know , what is the maximum frequency of mobile speaker </p>
  
  <p>look at this image :</p>
  
  <p><a href="https://i.stack.imgur.com/NjlrV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NjlrV.png" alt="Human hearing is in acoustic area , between 20Hz and 20KHz "></a></p>
  
  <p>I want to create and android application to generate sounds with particular frequency , but before that I want to know what frequencies can be generated by mobile phone speakers</p>
  
  <p>what I really want to know is range of mobile phone speakers frequency  , and know whether can I generate infrasound  or ultrasound by mobile speakers , or any speaker.</p>
  
  <p>sry for my bad english</p>