The noise is a short burst that sounds like a sea otter Sounds like air to me, but I’m not a pro or anything.

I’m wondering what to do. There’s no flooding, the water runs evenly from the tap and flushes properly. The water also gets hot.

When we run the water continuously (for longer than 15 seconds) the noise will come only once and remain silent.

Is there air in the lines? Do I have to run the sumpump or anything? The house is 6 years old.

Any advice would be appreciated.
The problem has been solved. Thank you to those who answered, you helped me just to open my mind a little. I heard the noise once more when the water wasn’t running and I realized, I’d left a hose on outdoors earlier today. I ran out and shut it off, and tested the water and the strange noise stopped. Thanks again!

If so I am about to break the Law.