I have a dullness in my right ear following having the flu, i have had my ears syringed a week ago but still cannot hear properly?

Fluid behind eardrum: Often during or after a viral infection, fluid can accumulate behind the eardrum causing a feeling of fullness and dullness. It's not necessarily a bacterial infection so it doesn't always have to be treated with antibiotics. Decongestants and intranasal steroids can help, but if it's persisting, then evaluation with an ENT is sometimes warranted. Best of luck!