What stimulus levels should be used to verify average conversational speech when performing real ear measurements in children?
Verifying hearing aid performance for average conversational speech is usually aimed at measuring the frequency shaping of the fitting for use during conversations in quiet. One such situation has been well-described in the literature: a talker uses a normal vocal effort and is directly in front of the listener, with about 1 meter spacing between talker and listener (Byrne et al, 1994, Cox & Moore, 1988, Olsen, 1998). In this situation, most people produce speech that is about 60 dB SPL, overall. If the talker is closer, or if the talker uses a raised vocal effort, higher overall levels in the range of 65 are also realistic (Olsen, 1998). An input level of 70 dB SPL, however, is closer to a loud vocal effort, and is likely higher than what truly reflects average conversation. In practice, it is often useful to perform verification measures using levels that help us verify WDRC hearing aids. This suggests two things. First, it helps to verify the frequency shaping of the fitting above t
