With human-descended cultures and associated xenosopohonts spread out over 3000 cubic parsecs, hundreds of thousands of forms of communication are in use. While regional trade languages exist, the problem is mostly side stepped by the use of translation software. Upon arriving in a new place and connecting to its metascape, any necessary translation software integrates itself seamlessly with a visitor's netlink. Only the most backward or isolationist habitats deny complete translation, and even most of those find it expedient to allow limited translation of signage, official communications, and the like.
The visitor will hear speakers in their native tongue (though their netlinks will note the actual languages used), unless they utilize more primitive visual-only links, in which case the translation will appear as "subtitles." For those with a need to blend in, direct neurologic download of language software is employed. This was once more widespread, but it's susceptibility to hacking proved its undoing.
The most notorious of these attacks was caused by the "23 Enigma" virus in the time of the Radiant Polity. It is believed to have been perpetrated by a hacker collective called the Nova Mob, though there was never any official statement of responsibility. The virus was named for a quirk (or perhaps a signature) in its code that left its victims unable to speak the words "twenty-three." Instead, they would replace it with a close approximate ("twenty" or "twenty-five," perhaps). The virus was a bit of nanomachinery, phage-delivered into the microbial vector employed to carry the translator code to the brain of biologics. The changes caused a global aphasia and lowered stress tolerance, leading to explosive reactions when communication with anyone was (predictably) ineffective. This reaction was particularly pronounced against moravecs and infosophonts, likely by design.
The malware vector was aerosolized, so it spread quickly throughout habitats. Quarantines were put in place, but these were often policed by bots, which only intensified the anger of the populace. It was weeks before the virus was contained in the most places and civil order restored.
For years afterward, it was a frequent conspiracy theory in the noosphere that hacks of Enigma 23 existed that were more subtle, that shadowy forces were using it to surreptitiously shape the language (and therefore the thought process) of the populace.
2 hours ago