It is possible to get a deviation on the Class 1 medical from the UK CAA which will enable you to get the CPL and depending upon your circumstances you may be granted full Class 1 privileges if your hearing has not deteriorated which will enable you to obtain a full ATPL. The deviation does also depend upon how bad your hearing is in the first place. If its lower than the renewal threshold you may have problems. All this is also assuming you are applying for a medical from the UK CAA, im not sure about other authorities and their standards. Hope that helps.
C250