The HCSR04 ultrasonic range sensor is a cheaper and more common measuring device than our current ultrasonic sensor.
In order to integrate it into our engine, we used the NewPing library.
During the QA process we encountered a conflict between this library and the built-in Arduino Tone library since they both use timer 2.
To solve this we replaced the Tone library with TimerFreeTone, which, as you can understand, doesn’t use a timer 
Now the components don’t conflict with one another and you are free to use them together in your cool projects.