Thank you for confirming.
I could help you to disable the voicemail indicator, but doing so only clears the indicator, the underlying problem would still be there.
You have an active voicemail service being provided by your phone company/carrier. So long as that is there, you'll keep getting messages, which is what the beeps indicate. People have been leaving you voicemail messages.
You should dial into the voicemail (usually dialing *98, or your home phone number) to check the existing messages so none are missed.
Next you will need to call your phone company, and ask them to cancel/remove the voicemail service from your account.
With that done, the issue would resolve itself.
If you want to just disable the indicator, you can , but again the underlying problem would still be there and you'd continue losing messages until you had the voicemail service removed.