Thank you for your post.
Pendred syndrome is a condition in which affected people to lose their hearing as children, and often develop thyroid problems, such as goitre, later in life. It’s caused by mutations in a gene called SLC26A4, or pendrin. I’m not sure from the information given whether that is the cause of this person’s hearing loss/goitre, but there is a lot more information about Pendred syndrome here: https://www.nidcd.nih.gov/health/pendred-syndrome
In addition, an underactive thyroid gland, or hypothyroidism, can cause both hearing loss and goitre – there’s more information about this on the NHS website: https://www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/
We can’t give out medical advice, so we can’t advise on your question about surgery, but there is some information about that on the NHS page about goitre: https://www.nhs.uk/conditions/goitre/
The only advice we can really give is for them to speak to their GP about this, who will be able to help them to get a diagnosis, and advise them on the treatments available.