At first I should admit I have very limited knowledge about sounds and working with them.
I have hundreds of old files, low quality recorded lectures, most probably recorded on cassette.
Is there any way for me to improve the quality and make the speech more clear? After that I have to make it louder too.
I have used "Noise Reduction" of Audacity and managed to remove the basic noise, but the speech quality is yet unacceptable. Here is 10 seconds of files, before applying any filters:
Thank you in advance