Most everyday communication is handled via datapads and wireless networks and takes the form of video conferencing. Over short distances, this communication is relatively reliable and instantaneous.
Military, scientific and tactical teams often make use of small but very powerful earbud Communicators for mobile, hands-free communication. Despite the devices' small size, they include a beefy processor capable of data encryption and a powerful antenna to maintain signal in a variety of environments.
The recording nature of the devices works primarily on vibrations, allowing for even whispered speech to be received clearly on the listening end.
Datapad communicators are nearly always filtered through automatic translators to handle intercultural conferencing. The translations are offered both as automated captions (which are fairly reliable) and a variety of synthetic voices speaking in the owner's designated language, either at a slightly louder pitch or replacing the original audio entirely (user's choice).
These translators can be used with any language to allow for instant captioning for those with aural disabilities. They also support translation of sign language into text or speech with a reasonable reliability.
While core language is captured by translators, some idioms are tied to local cultural concepts and may not be immediately understandable by an outsider. The core of the message, however, will come through.
Sound waves have a set speed, as does light, so even sound sent as data can only reach a receiving system at its maximum speed. On the same station, this delay is typically too short to be perceived. From orbit to the planet, it is too small to be a major inconvenience. Any greater distance, however, and the disconnect between when a message was sent and when it's received becomes noticeable.
This makes communication difficult across a system, and nearly unthinkable outside a system. For those situations, a few rare communication devices designed by the Zuxian allow for more rapid communication via quantum entanglement (QE).
The QE machines leverage electron pairs between QE communicators, allowing the spin of one's electron to instantly be matched at the remote location with the other's. This is the only way to bypass the light-speed limit directly for purposes of communication.
Despite having a limited understanding of Zuxian tech and quantum entanglement, this technology has yet to be replicated by Sirian Humans Part of this difficulty is that even QE machine can only be paired with one other machine, and a paired machine is required for it to have any effect. One can't simply call the other end of the galaxy unless a paired device got to the other end of the galaxy already.
One other facet of QE communication is that it can't be intercepted. Because it functions on paired electron vibrations rather than transmitting data across open space, there's no 'hacking' a QE communique without listening in at either the sending or receiving end.