Ah, ah, ah, ah =1+1+1=1* 4;

Woo woo, woo woo = (1+1+1)+(1+1) = 3+3 = 3 * 2;

Meow meow = (1+1)+(1+1)+(1+1) = 2+2 = 2 * 3.

Think of onomatopoeia as "1", that's all.

It can also be seen as the number of words in each group * the number of groups.