A short summary on my theory regarding echolocation being used by UA/UP/Barny to communicate.
1. Artifact is transmitter - sends echolocation signal into "glow" star of nebula (the star that gives a reflective nebula its luminosity eg Merope) This boosts the signal across the whole nebula.
2. Probe is reciever - Take it to a planet suitable for growing barnacles and it receives the transmission from the Artifact. Perhaps in space it points to the best suitable planet in a system?
3. A baby barnacle is born and my dreams come true
Some facts about echolocation that also fit with UA/UP/Barny;
animal echolocation has only one transmitter (UA) and two receivers (UP).
Whales in the same area will sing the same song, but it is slowly changing and evolving to adapt to the environment.
It has been suggested that humpback songs communicate male fitness to female whales. (barnacle mating call)
Echolocation allows the odontocete to easily discern the difference between objects that are different in material composition, even if visually identical, by their different densities. (searching for planetary grow site)
What you take from these facts is up to the individual. Personally I think the Artifact, the probe and the barnacle are 3 parts of the same entity, and echolocation is the how they communicate. This further strengthens my theory that these things are sentient beings, not just bio genetically engineered tech.
As for how these entities learned this form of communication, I have a theory it is to do with the "Voyager golden record". For now I just want to get these facts up. Hoping that this format of post is easier for people to read and understand what I'm saying.