Unless you live in Cambodia, South Vietnam or maybe Long Beach, California, speaking Khmer isn’t likely to give you a global competitive edge.

But as a group of linguists meeting in Siem Reap earlier this week sought to emphasise, the Khmer language’s niche status in the modern world shouldn’t be confused with historic isolation.

“People think that Khmer is on its own, but they’re completely wrong,” says Gerard Diffloth – a key speaker at the sixth annual conference of Austroasiatic languages, which took place for the first time in Cambodia earlier this week.

“Khmer is related to more than 100 languages in the Austroasiatic family, but most of them are not well known – they’re small languages. Most people don’t know about these things.”

Believed to originate in the Mekong basin and dating perhaps to 2000 BC, the common genealogy of the Austroasiatic (which translates simply from Latin as “south Asian”) languages was debated and dissected by international experts during the three-day conference.

Papers ran the gamut from the intriguing (“Taboo words in Khmer society”) to the seemingly impenetrable (“A study of discourse words formed on pit in Khmer”).

“It’s a wonderful subject,” enthused Krisna Uk from the Centre for Khmer Studies, which co-organised the conference with the Royal Academy of Cambodia.

“You could almost compare it with archaeology, except you’re not studying stones, you’re studying letters and sounds. You reconstruct an entire civilisation out of these patterns of language and patterns of changes.”

From its origins in the Mekong basin, the Austroasian family now extends to languages currently spoken by small ethnic groups as far afield as India, Malaysia and the Nicobar Islands – one of the most isolated archipelagos in the world.

Reconstructing the links between the existing languages is a dry, technical business in which sounds and vocabulary (grammar and alphabets change too quickly over time) are crosschecked against each other for commonalities and mutations over time. Diffloth – not unusually – was a mathematician before he became a linguist.

But the linguist is quick to emphasise that his is also a deeply human enterprise, never more so than when it comes to unpicking the common roots of the two most prominent Austroasiatic languages: Khmer and Vietnamese.

“That is something that people just cannot swallow,” he said.

Diffloth explained that while Cambodians were amused and interested to learn of Khmer’s links with niche dialects elsewhere in Asia, this curiosity did not extend to discussion of Vietnam.

“They are very unhappy with that for all kinds of reasons that have nothing to do with linguistics,” he said.

Nathan Badenoch, an anthropologist-turned-linguist who also spoke at the conference, said he understood the problem, describing language as automatically weighed down with “cultural baggage”.

“It’s difficult for many people to put aside the history and that kind of stuff and accept the fact that there may be a historical relationship between people that they really don’t want to see.”

He added that the seemingly vast differences between the neighbouring languages made it particularly harder for people to swallow.

“Vietnamese has got all these tones, these one-syllable words, people know that they borrow a lot of Chinese words and they write in the Roman script,” he said. “Khmer borrows from Sanskrit, it’s got words of two syllables … everything points to something that’s very different.”

The inextricable linkage of language and identity is a theme that permeates Badenoch’s work.

In the communities he studies in northern Laos, whose language he describes as a “distant cousin” of modern Khmer, centralisation caused by the rubber farm economy is creating large villages with eight or nine ethnic groups living together – a fact that will almost certainly speed up the loss of small languages.

“The number that’s often quoted is one language every two weeks is disappearing,” he said.

“No one’s really sure, but I think it’s a fairly good indicator of the seriousness of the problem.”

Badenoch emphasised that preserving linguistic diversity didn’t mean encouraging people to stick to languages that might limit their options for communication.

“Most of the world is bilingual or trilingual,” he pointed out, describing a key aim of the conference as raising “the appreciation of diversity not as something to overcome but as something we can use.”

Diffloth echoed the assertion that language preservation was among the conference’s key imperative, emphasising that there were communities within Cambodia of “perhaps 100 old people” whose languages would die with them.

However, he refused to name the communities where this was happening, arguing that the work of preservationists was not aided by public attention.

“Imagine somebody finds something extremely old and extremely interesting somewhere and it is publicised, he said – using archaeology as an analogy.

“Ten thousand people will rush to the scene and it will be completely wrecked.”

“There’s no need to dramatise it so that people come and be curious. I think it’s not a good idea.”