Are haiku typically "padded" when read aloud?

Question

I was once told that haiku should be "padded" so that instead of 5/7/5, they fit an 8/8/8 meter:

■■■■■□□□　←　wait for 3 beats after this line
■■■■■■■□　←　wait for 1 beat after this line
■■■■■□□□　←　wait for 3 beats after this line

If I recall correctly, the explanation was that Japanese favors rhythms in groups of 4 or 8 beats (morae). I don't actually know if haiku are read this way, though--it's just something I was told once.

Are haiku actually read aloud with these pauses? Or is this something my friend made up?

Answer 1

Yes, I think you'd read it as:

■■■■■□□□
■■■■■■■□　
■■■■■□□□

for 5/7/5 like かたつむり・・・ where the middle line can be split into 4+3(e.g.: トウキョウ・ナゴヤ).
And you'd read it as:

■■■■■□□□ 　
□■■■■■■■　
■■■■■□□□　

for 5/7/5 like 静かさや・・・ where the middle line sounds better when split into 3+4(e.g.: カワズ・トビコム).

And you'd probably read it as:

■■■■■□□□ 　
■■■■■■■■　
■■■■■□□□　

for 5/8/5, like 8/5/8/5/8/5... :D(唱歌・カタツムリ、童謡・鳩より)