First check in TapSports Baseball's game settings to see audio is disabled audio.  If you have enabled audio within the game itself the sound may be off on your device.

For iPhones:
Check the switch on the side of your iPhone, the one above the volume controls. Toggle its position to the other setting and try the game again. Evidently this switch may make some games treat it as mute switch

For iPads:
In Settings>General There is an option "Use Side Switch to: Mute System sounds."  If this option is selected, the switch on the side of the iPad above the volume rocker will mute system sounds. Change this setting if you do not want that switch to mute sounds.