if(open_con(F,"localhost","port"))
{  
   $text = "some expression to be send to the server";
   syswrite(F,$text,500);
   open(AUDIO,">$audio_file);
   $receive = <F>; // instead of sysread(F,$receive,500) 
   while($receive = <F>)
   {
      print AUDIO $receive; 
   }
   close AUDIO;
}