Description and validation of an LDL procedure designed to select SSPL90

A new procedure is described for measuring loudness discomfort levels (LDLs) for the purpose of selecting SSPL90 characteristics of hearing aids. The person is seated in sound field wearing a high-output hearing aid (with a known amount of 2 cm3 coupler gain) connected to a personal earmold. The loudness of frequency-specific signals is rated from a series of loudness category descriptors. The LDL is defined in terms of SPL developed in a 2 cm3 coupler, thus making selection of SSPL90 from hearing aid specification sheets practical. Experiments on LDL stability over time and validation of the SSPL90 selection are reported.