To the gentleman who occupied the other elliptical machine tonight at the gym:
It is true that listening to music via headphones makes it difficult to hear other sounds in the room where you are exercising. It does not, however, mean that those sounds go away. That includes the self-encouraging shouts and exclamations you make to get through your workout, which were made at a level that overrode both the television in the room and the headphones used by others.
Your prompt attention to this matter is appreciated.