You have of store credit. To use it, simply place your order and you will be able to choose store credit as the payment method when it comes time to pay for your order.
Headphones and ear plugs are other essential accessories for most musicians. Most ear plugs are designed so that they only cut out the harsh frequencies allowing you to hear properly without damaging your ears. A lot of session musicians actually use ear plugs as well as headphones when recording, as the volumes are turned up so loud that it is almost like playing a live gig! So why not buy a set of both?