The sounds of sex

I think one of the things that really excites me is the sounds of sex. I am not talking about moaning or orgasms; those are nice too but I am really talking about the sounds my sub makes when I dominate her. I love the sound of her gagging on my cock. I love the coughing, spitting and hard breathing that happens after I let breath after holding my cock deep in her throat. I also love the sound of my hand slapping against her face. It has to be done just right to get the right sound but when I get it, it really cranks my motor. Spanking is another activity that can have a great sound if done right. Cupping my hand slightly seems to increase the slap sound and consequently increase my enjoyment.
My sub doesn't like to make a lot of noise. She resists crying out and she doesn't like begging but the little noises she does contribute to the overall pleasure I get. Gagging my sub tightly and then ask her lots of questions is also very enjoyable. She struggles hard to answer and the answers are difficult to understand but those are just more great sounds and reinforce my feeling of dominance.