Ah-rah-kah-wah
* Ah - like the "a" in "father"
* rah - like the "rah" in "rah-rah"
* kah - like the "kah" in "kah-booom"
* wah - like the "wah" in "wah-wah"
It's important to note that the "w" at the end is pronounced as a "w" sound, not like the "u" in "flute".
There might be slight variations depending on the speaker's regional accent, but this pronunciation is generally accepted.