In my experience, my brain has always tried to naturalize the sounds that have changed due to HA program changes such as hollow or own voice sounds different. For me, it usually takes about 3 weeks for the strange sounds not to sound strange any more. This is what makes it so confusing when trying to assess whether we like a program change or not. I now make a point of not running back to change the program due to strange sounds for at least 3 or 4 weeks; to give the brain time to accomodate. For those who have never worn HA’s before, and have just been fitted, I suggest you live with the weird sounds for at least 3 months, yes I mean that; maybe longer. Speech recognition for me, becomes better and better as time goes by (months). This is all based on wearing them all day, every day.
Anyone ever see the silent movie documentary where a person had special viewing device attached to his face which visually turned the world up side down? After a period of time, his brain inverted the image and he saw normally. After removing the device, what he say was now upside down and it took a while for his brain to correct the image. This shows what the brain can do to accomodate changes.