Floor noise tongue groove
Are the joist 16" oc? If not you may want to sister them for added strength, and give you a better nailng/screwing surface. The 1/4" doesn't give the best support for subflorring, so you need to upgrade to 3/4" or at least 1/2" plywood. It's also a good idea to use a glue like liquid nails or other adhesive over the joist. Your fastners should be placed about every 8 inches. Good Luck!