Scatter plot of the C-weighted peak sound pressure levels measured at the ear simulators of the HATS against the mean ratings of discomfort. The type of symbol indicates the type of stimulus. Black symbols correspond to the normal hearing test subjects (NH), and the values of the hearing impaired subjects are color coded depending on the type of hearing aid. Moreover, the settings of the hearing aids FIT INR OFF and FIT INR ON are marked with a horizontal (“–”) and vertical (“|”) black line, respectively.