The requirement to memorize and recite, or "turn in" a proficiency lecture of a series of questions and answers for each degree originated with the Grand Lodge of Louisiana in 1850. Since then, most jurisdictions have adopted this means of insuring a new Brother has at least a fair idea of what the degree is all about. Some (very) few states have dispensed with it, but the norm is that the lecture must be learned and turned in. In addition to Iowa, I understand that Missouri may have dispensed with the lectures, (though I believe Brother Truman may be rolling in his grave over that ;-) )
Arkansas requires that the EA and FC lectures be memorized and turned in prior to the candidate being advanced to the following degree. This may be done in open lodge, or in committee, with the committee subsequently reporting either "favorable" or "unfavorable" to the lodge. Per the Digest of Laws, the proficiency should be turned in within six months or the candidate must request and extension from the lodge, but this rule is currently not enforced. The Master's lecture must also be memorized and turned in, but there is no enforced time limit for this, other than that the lecture must be turned in before the member can serve as one of the principal officers of a lodge.
Arkansas is one of the jurisdictions where the lectures are learned mouth-to-ear, the only parts proper to be written being the paragraphs on the working tools.