It is popularly supposed that the purpose of speech is the transfer of factual information. However, it can be forcefully argued that factual information transfer is secondary to a more important task. That is the identification of the speaking individual.
One mechanism is the astonishingly accurate aural memory which recalls past encounters.
Another is the identification of the origin of people newly encountered.
People are identified by their speech (in parallel with a myriad of other animals which utilize vocal identification). The “language” spoken is the most powerful identifier of origin but many subsidiary traits like dialect, accent, phrase choice and argot all allow specific identification. This is not to say that most humans can determine the source of origin of another by their speech. The vast majority cannot, although a few exceptional individuals can.
Instead speech allows the binary assessment as to whether or not an individual is from the same area or “clan” as the listener. Perhaps much of this is subliminal, but it is nevertheless provides an important differentiation between a “local” and an “alien”. An individual from the same region is, perhaps, more likely to be a “friend” as well as a possessor of numerous other features which allow alignment. These include cultural , genetic and other similarities to be later identified and subsequently resolved.
Finally, there are interpretations which allow assumptions that greater safety is assumed to be the case in encountering a “local”. This aspect of language is implanted early in the child – far earlier than other cognitive skills and, once implanted, difficult to eradicate. Not only is language branded on the individual, but the ownership of this vocal identification is precise enough to preclude emulation.
Said another way, speech is a complex and secure password.
With the migration of aliens into Europe in large numbers in the 20th and 21st century the progeny, -carrying with them different cultural and genetic values – have been exposed to and have adopted the vocal traits of their area of implantation. Effectively they have acquired the “password” of that society and, at least vocally, cannot be distinguished form the natives.
Whether this produces a cognitive dissonance – the contrast between ownership of the language password and outward appearances and behaviour – is difficult to know. However, this is possible and if so is likely to become an arena of dissonant stress.
There is an irony in that the very word dissonance has as its origin a reference to sound.