Look at an app called Timeriffic (probably spelled wrong). It allows you to set certain functions of the phone to happen at certain times. It should allow you to set the phone to ring audibly at certain hours and turn off all other notifications.
The key to remember with timeriffic is that you have to start at the earliest point in the day and put all of the steps/toggles in order. If you decide that at 3:00pm you want the phone and every thing else to be full blown, and 5pm you want everything to be silent until 9:00pm, then go back and decide that you want to be audible again from 6pm to 8pm... you need to delete the 5 to 9pm setting, and add a 5 to 6pm setting, a 6 to 8pm setting and then a 8pm to 9pm setting. Everything in order.