Word: an inability to understand a spoken language

Illiterate is used to describe someone who cannot read. I am looking for a word to describe someone who cannot understand a spoken language.

David was [unable to understand French] {People are speaking french around him}

Jean's friends were laughing about a joke, but David was [unable to understand French] and didn't know what they were laughing about

Not-fluent is the obvious compound, but it is rather inelegant.

David was not Francophone!

This reply is from a "Hispanophone" who spent 40 minutes searching for the word "árabohablante" (Arabophone?) on the internet in 2021.

Perhaps this can help someone else in the future :) Godspeed to you!

@fev: thank you for your comment. Following your suggestion, here is what the Oxford English Dictionary says about the word Francophone:

Origin: Formed within English, by compounding; modelled on a French lexical item.

Etymology: < Franco- comb. form + -phone comb. form, after French francophone, adjective (1880) and noun (1894).

Forms: also with capital initial.

Meanings:

A) Noun → A French-speaking person. Example: "The study employs the terms anglophones, francophones and ‘others’ to denote respectively those who speak English, French or another language in their homes." (1969. Daily Colonist. (Victoria, Brit. Columbia). 5 July 5/1)

B) Adjective → French-speaking. Example: "The new poet laureate of Canada is Pauline Michel. Every report of her appointment identifies her as the first francophone writer to hold the post." (Times Lit. Suppl. 26 Nov. 16/2)

@KillingTime. I understand your point. However, this reply is only an alternative that may be useful to some :) Cheers!

How about auditory aphasia or acoustic aphasia. It doesn't mean that he can't understand a language due to brain damage or hearing loss but there are other unknown reasons.

Here is another link.