Sony on ear headphones, foam a bit worn (Westbury Fields BS9)

Sony MDR-ZX110AP on ear headphones. They are standard headphones but if worn right on the ear they do block out some background noise. The foam on one had started to go quite a bit and the other is just starting,seephotos. I do not think you can replace the foam bit. Some life in them still for occasional use. They fold i for storage or carrying.