These are two main kiai (used) one for calling or pulling your opponent toward you (TOH!) and the deciding kiai.
This final kiai is executed in two ways: a short, forceful “EH!” to accompany and strengthen cuts and a piercing “spiraling” manner “Eeeeehhh!” to enhance thrusts.
Smoothness of breath and the maintenance of postural integrity while breathing deeply are emphasized.
From Old School: Essays on Japanese Martial Traditions, Ellis Amdur