For a few weeks now I've been noticing that when I play the 7th fret on the 6th string a get a weird squeak mixing into the sound. Here is audio of me playing the 6th string up to the 7th fret and then some frets around it:
I haven't noticed anything l that on other frets and strings an upon visual inspection neither the string nor fretboard appear in anyway different on that fret. What could be causing this?