No matter what my audi does, my acoustic and classical guitars always sound awful when I get home after a session with her. I have done some reading (references 1, 2, 3, 4, 5) and devised a method to improve the musical experience. As a layman in the field, I would like to hear your comments and suggestions on things I got wrong and ways to improve this little experiment:
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Spend some time experimenting with domes and molds. Find the perfect acoustic setup for you. My ear canals are too narrow for custom molds, so I choose domes that give me both good audibility and physical comfort.
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Do a REM session or in-situ audiometry. There is a rich discussion on “REM vs in-situ audiometry” here (Real ear measurement vs. in-situ audiometry). Either way, it is important to input your conductive results, so you get the most optimized prescription.
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Create a music program with a fitting formula you feel more comfortable with. If needed, test all available to you. I’ve settled with DSL, though I don’t really like it for speech comprehension.
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Disable all digital features you can in the music program: feedback manager, digital processing, voice booster, etc. Leave this program as much closer to an “analog” program as possible.
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Lower the target soft gain until you get a linear compression rate (1). The gain curve should have about the same general shape as the one you started with. Adjust for volume. I do that playing my guitars.
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Get your “eq” right (if that is important to you): when playing your instrument, it is easy to get sidetracked by what you want it to sound rather than what it really sounds. This has been the most difficult part to me, by far. There are multiple threads and posts in this forum addressing the many ways things can go south between your hearing aid and your brain. Here is what I did:
a. I created an audio to test frequencies using the “equal-loudness contour standard” (reference here)). Edit 2 (new frequencies): The frequencies in the audio are (Hz): 125, 250, 500, 625, 750, 1000, 1250, 1500, 1700, 2000, 2300, 2600, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 7000, and 8000. Edit (new file): Here is the link for the audio.
b. Play the audio and adjust the volume in your speaker so that 1 kHz plays at edit (new volume) 65 dB.
c. Check for your perceived loudness across all frequencies. Your music program is optimized if this perception is even across the board. Otherwise, adjust the gains in your program until you perceive all frequencies at the same volume. -
Throw back some compression accordingly. Edit:: Here Oticon recommends to: 1) “keep the compression ratio as low as possible while ensuring sounds are audible to the listener”; 2) “most compression is done between the first two knee point levels (soft and moderate)”; and 3) “The compression ratio is kept to 1.0 between moderate and loud knee points”. I have a purely conductive loss in my LE, so none there. Things are a bit more complicated with my RE, but I still manage to have compression as low as possible there.
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Play music and hear how it sounds. I am happier with my music program now, though I still feel the low frequencies on my classical guitars are not quite there yet.
Getting the music program right is hard. I’d appreciate any feedback/comments, especially on step 6.