A method and apparatus for dynamically adjusting the level of a response signal from an ultrasound transducer is disclosed. During a calibration phase, a description of a gain profile of a level adjuster is set dependent upon an expected response signal for a type of object to be tested and the description is stored in memory. During a measurement phase for an object under test, a description of a gain profile is selected for the type of the object under test and a gain profile is determined from the selected description. The response signal from the object under test is passed through a level adjuster and the level of the response signal is adjusted dynamically in accordance with the gain profile. The description of the gain profile is selected with reference to an expected response either by operator interaction with a user interface or automatically.