Ujjayi breathing, or throat breathing, is sometimes called ocean breathing. To practice, we contract the larynx very, very slightly while inhaling and exhaling, narrowing the air passage. The sound is soft and similarly to the whisper of the ocean. Ujjayi breathing helps us regulate the breath and focus the mind, when we listen to the sound of our breathing.
To get a feel for the practice, open your mouth slightly, then exhale through your mouth making a haaaaaaa sound, like you are fogging up a mirror.
Inhale through your mouth creating a soft ahhhhhh sound.
Practice breathing this way for several repetitions.
Gradually close your mouth so that you are breathing through your nose, while still making the ahhhhh sound on the inhale and the haaaa sound on the exhale.