All are tuning fork tests except

Cold-air caloric test: This test is done when there is perforation of the tympanic membrane because irrigation with water in perforation is contraindicated. The test employs Dundas Grant tube, which is a coiled copper tube wrapped in cloth. The air in the tube is cooled by pouring ethyl chloride and then blown into the ear. It is only a rough qualitative test. Ref: Dhingra 6th Edition pg no 43