changing this "ding.wav" sound on QM and MC

This “ding.wav” sound comes up very often and I am trying to find out what sub features are creating it and I am trying to change the sound so it would really tell me what is going on since one sound for everything is as good as no sound – only more annoying and I can not point any directions.
Meanwhile I have changed the line alarms on another sound but how do you change the sound on the QM for the TWS connections? I just want to know what is going on when something is happening when an alert is coming up.
Are there any other sub features creating this sound - and when yes how do I change that?

Haven't test it:

Regedit:

HKEY_CURRENT_USER\Software\TS Support\MultiCharts\TraderServer

HKEY_CURRENT_USER\Software\TS Support\MultiCharts\MainForm\MC\MCCharting\ChartManager\AlertDefaults

There are Soundoptions...