Hi, @userDHxbvLTk6G I hope you are doing well.
Thank you for this question. I understand you are having problems with your device at the moment and I would like to assist you to troubleshoot this problem.
first, we need to clean all the speaker output on the device itself it should be on the opposite side of the headphone jack port. make sure to use an esd safe brush to clean the speaker vents.
clean the top receiver too for better clarity of audio. "Make sure to remove any case or stickers on the device
test the device if it improves. it the audio quality doesn't improve the worst-case scenario your device might need to be serviced for a speaker replacement.
For device servicing, I would suggest contacting 1-800-SAMSUNG or check https://www.samsung.com/us/support/service/locations/ if there's a Samsung Authorized Sevice provider near you.
hopefully, this will help with your problem
Be sure to click " ✔ Accept as Solution" When you find an answer that works for you
Your top speaker might be clogged, try using some tape to pull some dust out and a soft brush to clean some of the dust away.
Alternatively, you can dial *#0*# and press speaker to test both the top and bottom speaker (black arrows indicate which speaker is enabled). If the top speaker isn't very loud, it may be clogged and need to be cleaned. It may also be going out and need to be replaced.
I have this issue strated 3 days ago. All i did is just rub and clean my upper speaker of my note 8 with dry clean brush. Guess what, it works like a charm. Try it, its worth trying. Work for me, hopfully work for you as well.