Abstract: A hearing aid fitting system comprising a computer with fitting software and having a display for displaying parameter settings of a hearing aid and input means for adjustment of the parameters, characterized in that the system further comprises a camera for recording images of the wearer's head including the ear with the hearing aid, and a display for displaying at least one image received from the camera.

Abstract: A method to measure both the isothermal secant and tangent bulk modules and the density of functional fluids. The instrumentation and methodology described in this invention use much smaller volumes of fluids which permits the measurement of these critical properties on experimental fluids which are available in only limited quantities.

Abstract: A method is disclosed for determining bulk modulus of a liquid based on a pressure-volume-temperature relationship at constant volume corrected for changes in system volume due to elevated pressure and temperature. The apparatus used to determine bulk modulus comprises a pressure vessel in which the liquid to be tested is introduced, and from which all gases are removed. The vessel is placed in a constant temperature oven and the pressure is recorded. The method for determining bulk modulus and density requires calibration of the vessel volume changs due to pressure and temperature.