Digital Clock Circuit With A Buzzer
See http://www.ti.com/lit/ds/symlink/ne555.pdf, page 9. This will provide a beep on the hour, with a duration set per the data sheet.

Also, you need to make a debounce circuit for your "advance minutes" switch.

Your reset circuit for the hours will not work as you think it will. As soon as the clock hits 23 hours it will reset. I suggest detecting 24 hours and using that to reset your 10 hour counter. The delay through the and gate and the or gate will provide enough delay to reliably reset the counter.

Tie all of your unused inputs high or low - don't let them float. You don't indicate what process chips you're using. If CMOS (74HC), tie the inputs directly to ground or power. If 7400 or 74LS, use a 1K pullup resistor to tie high, ground for low.