RustyCrampon wrote:

Can anyone recommend a better noise-blocking solution? I don't mind
spending a few hundred pounds if necessary.

Etymotics in-ear phones with custom earpieces moulded to your ears.
Etymotics used to sell a pack of the earphones with a voucher to take to a
hearing aid specialist to get the ear inserts moulded. Very comfortable and
extremely good sound.

I use mine on aeroplanes to block out engine noise.