The open Master Hearing Aid Forum

Hello, I was going to be doing some testing using the NAL-RP prescription rule with flat loss profiles of 20 dB and 40 dB across all frequency bands. When I load those specified audiograms, I see the curves in the above^ picture. Assuming I'm trying to measure insertion gains at 65 dB, would it be accurate to interpret that the red curves seem to indicate that for a 65 dB signal, there would only be attenuations applied across all the frequency bands? The red line seems to fall below 65 dB SPL. I'm a bit confused as to why the actual target REIGs specified wouldn't be above 65 dB SPL.

Or is it the case that simply creating a fit with NALRP specified is not sufficient? Do we have to change the gains/maxgains for each of the frequency bands?

Your graphs for 20dB pantonal hearing loss show amplification for frequencies above 500Hz. Please refer to the openMHA Fitting GUI manual for an explanation of the display. I hope this helps, please ask follow-up questions here if anything remains unclear so that we can improve the documentation.

Thanks for sharing the fitting manual. That was very helpful. One question I have is whether the matlab fitting tool has a tool for measuring the actual real-ear insertion gain values within each frequency band? I understand that the LTASS panels show the insertion gain targets but it would be really useful to have the functionality to display the actual real-ear levels within each narrow band somehow. Is this a current feature by chance?

No, this is not a feature of this GUI. In order to access all insertion gains, you would have to extract (with mha_get()) the gtdata matrix from the MHA dc plugin that you have just fitted.