Thank you very much for your response and explanation. I unfortunately can't even start to comprehend all of the concepts you are talking in. But it opened my world a bit.
My level of expertise right now is about as high as choosing the right part if i know what to look for , and go/learn from there.
Maybe someone has experience with other ultrasonic sensors and can elaborate, if some of them are more silent than others? Whatever the range or accuracy or interface. Or some literature which could be useful on the subject.
Thank you!