change in cat meow

My cat's meow suddenly went much quieter and sounds almost hoarse, thought might be furballs but still the same a week later - any idea what might be wrong?

A vet visit might be a good idea. Could be a number of things that would be impossible to diagnose without a check-up. Is your cat still eating/grooming/purring normally? Can you feed her some Vetbasis Hairball Gel (http://www.vetbasis.com/prod_cat_hairball1.asp) or butter to see if that helps?