How do I stop my Lumia 1520 from making a sound when speakers covered?

[Windows Central Question]

How to stop Lumia 1520 from making a sound when speakers covered?

My phone never made the sound before, then after a month of having it the phone started playing a sound occasionally, possibly an xylophone-like sound. I never knew why (i suspected it was from being unlocked, but it happened more than just then) and now I have just realised it happens whenever my speakers are covered by my phone case (the kind with credit card holders that you fold back to use the phone) it's such an annoying sound and I have no idea how to stop it. Does anyone have any ideas? Has this happened to anyone because I can't find the same problem anywhere..

 

[Laura Knotek]

re:

Do you have any credit cards near the phone? It sounds like the phone is making contact with the magnetic strip on the credit cards and that is the NFC sound you're hearing.

If so, put the credit cards someplace else or turn off NFC in your phone settings.