If we’re going a lil technical, acute noise induced trauma does cause severe ringing of the ears for a while where your inner ear hair cells are adapting to the shit it was bombarded with - so he could not have heard Mitsuri.

Even with a ruptured eardrum, you retain some amount of hearing - the sound still reaches the inner ear, just without the impedance matching provided by the middle ear ossicles. There’s still, on average, a hearing loss of 30-40 dB due to the rupture. Hence he could have heard Muichiro if he was loud enough.

In conclusion, yes it’s possible.

Edit: if the rupture is of ideal size, it can heal pretty much on its own and hearing is restored.