It’s “arrr”, matey.
With a kindergarten teacher for a wife, plus kids in JK and Grade One, I'm constantly tidying up photocopied sheets on letter shapes and sounds.
Occasionally, my wife tells me, she has to discard sheets from British primers (aside: I still can't bring myself to pronounce this word properly, as "primmer"). You see, the English don't just speak funny by accident. They painstakingly learn it!
Both my parents are English, so I feel justified in making such comments. My mom's been in Canada for more than 30 years now, but I still enjoy posing questions to her which require the past tense of eat: "Well, Paul, I et it." Priceless!
Anyhow, last week I discovered this sheet, which purports to teach kids how to make the "Ahh" sound. You can do it three ways:

Yep, that's "ahh", as in "Drive your cahhh," "wish upon a stahh" and wave your "ahhm".
Action: Open your mouth and say WHAT THE HELL ARE YOU TEACHING THESE KIDS?!