It seems to deafen, but subsequent songs still affect the victim. Why is that possible? Does the deafen spell allow the same thing to happen?

>It seems to deafen, but subsequent songs still affect the
>victim. Why is that possible? Does the deafen spell allow
>the same thing to happen?

Bard songs still affect people who are deafened. This seems counter-intuitive but there have been a lot of discussions on this in the past. It boils down to game balance (e.g. not being able to completely nullify a bard by deafening yourself).

It's not exactly like the deafen spell. In general, it's a lot weaker.

This is intentional.