Take the following as truth: To a Western ear, the most predictable of language traits, perhaps, is the well-advertised Japanese use of r for our l .  Indeed, in my travels about Honshu during a three-month visit, I did hear  coinrocker,   see you rater,   Adurt Graphics  (dirty books),  blackwrrants  (hit-and-miss rendering of black walnuts),  Coffee Corombia  (a chain of coffee shops), and  Coconut Glove. 
Then the following statement: "There are many sounds that non-native speakers can not differentiate." is true, false, or inconclusive?
Answer: Inconclusive