I'm assuming you've tried basic earplugs with white noise generator at full power? When I used them to block out building construction noise, they worked well.

I'm assuming you've tried basic earplugs with white noise generator at full power? When I used them to block out building construction noise, they worked well. Maybe even too well - I was wondering if I'd wake up if a fire alarm went off. Active noise cancellation doesn't work well with noises like ambulance sirens.