Audio Editing Tools

Additive Synthesiser
Additive Synthesiser
Credit: Meettechniek
Harmonicarium
Harmonicarium
Credit: IndustrieCreative (Github)
Equalizer
Equalizer - Audioalter
Credit: Audioalter
Audioalter
Online audio editing tools
Credit: Audioalter
Audio_editor
Audio Editor
Credit: Beautiful audio editor
Cloud_bounce
Instant Audio Mastering
Credit: CloudBounce
If you want to test few of these tools you can download below given file, alternatively, you can use your own audio file.
Download Sample Audio file MP3 (Beethoven - Fur Elise (Short)).