If you’re hearing alerts in NinjaTrader, such as a doorbell sound, or r richochet sound, you’re probably hearing alerts from either indicators, or from drawing objects you added to your chart.
If you’re not sure which indicator or object is causing the alert, you can bring up the NinjaTrader Alerts Log, and it should help you identify the source of the alert. You can bring up the alert log in NT8 via the NT Control Panel’s New/Alerts Log menu choice.
Once you have the alerts log up, when you next hear an alert, check the log to see if it points you to the source. Then you can modify that alert as needed.