There are two rules about punctuation for the narrator:

• You can ignore punctuation when you narrate.
• You can not ignore punctuation when you narrate.

Punctuation is there to help the eye to group the words into meaningful units. When you make an audiobook, you are working in a different medium. The ear does not group exactly the same way as the eye. Punctuation is a guide, an approximation.

We use punctuation as learned socially agreed upon code symbols. It is an incredibly compact system. When we read “Great!”, we don't say in our heads “quotation mark Great exclamation point quotation mark”. We interpret the pair of quotes as someone speaking, and the exclamation point as expressing enthusiasm, and also as ending the thought (taking the place of a period). That's a lot of work for three keystrokes.

Test your punctuation skills

To show you the difference between reading and narrating, take this test.

Here is the beginning of Arthur Conan Doyle's The Sign of the Four. Undoubtedly you can read every word (Beaune is a French wine). but here is the real challenge: Try to punctuate this selection in the way you would read it out loud. Then look at the way it was originally written. I am willing to wager that your punctuation is not the same as Doyle wrote it.

chapter 1 the science of deduction Sherlock Holmes took his bottle from the corner of the mantel piece and his hypodermic syringe from its neat morocco case with his long white nervous fingers he adjusted the delicate needle and rolled back his left shirt cuff for some little time his eyes rested thoughtfully upon the sinewy forearm and wrist all dotted and scarred with innumerable puncture marks finally he thrust the sharp point home pressed down the tiny piston and sank back into the velvet lined arm chair with a long sigh of satisfaction three times a day for many months I had witnessed this performance but custom had not reconciled my mind to it on the contrary from day to day I had become more irritable at the sight and my conscience swelled nightly within me at the thought that I had lacked the courage to protest again and again I had registered a vow that I should deliver my soul upon the subject but there was that in the cool nonchalant air of my companion which made him the last man with whom one would care to take anything approaching to a liberty his great powers his masterly manner and the experience which I had had of his many extraordinary qualities all made me diffident and backward in crossing him yet upon that afternoon whether it was the Beaune which I had taken with my lunch or the additional exasperation produced by the extreme deliberation of his manner I suddenly felt that I could hold out no longer which is it to day I asked morphine or cocaine he raised his eyes languidly from the old black letter volume which he had opened it is cocaine he said a seven per cent solution would you care to try it no indeed I answered brusquely my constitution has not got over the Afghan campaign yet I cannot afford to throw any extra strain upon it he smiled at my vehemence perhaps you are right Watson he said I suppose that its influence is physically a bad one I find it however so transcendently stimulating and clarifying to the mind that its secondary action is a matter of small moment but consider I said earnestly count the cost your brain may as you say be roused and excited but it is a pathological and morbid process which involves increased tissue change and may at last leave a permanent weakness you know too what a black reaction comes upon you surely the game is hardly worth the candle why should you for a mere passing pleasure risk the loss of those great powers with which you have been endowed remember that I speak not only as one comrade to another but as a medical man to one for whose constitution he is to some extent answerable he did not seem offended on the contrary he put his finger tips together and leaned his elbows on the arms of his chair like one who has a relish for conversation my mind he said rebels at stagnation give me problems give me work give me the most abstruse cryptogram or the most intricate analysis and I am in my own proper atmosphere I can dispense then with artificial stimulants but I abhor the dull routine of existence I crave for mental exaltation that is why I have chosen my own particular profession or rather created it for I am the only one in the world the only unofficial detective I said raising my eyebrows the only unofficial consulting detective he answered

With punctuation and formatting, it looks like this:

Chapter 1

The Science of Deduction

Sherlock Holmes took his bottle from the corner of the mantel-piece and his hypodermic syringe from its neat morocco case. With his long, white, nervous fingers he adjusted the delicate needle, and rolled back his left shirt-cuff. For some little time his eyes rested thoughtfully upon the sinewy forearm and wrist all dotted and scarred with innumerable puncture-marks. Finally he thrust the sharp point home, pressed down the tiny piston, and sank back into the velvet-lined arm-chair with a long sigh of satisfaction.

Three times a day for many months I had witnessed this performance, but custom had not reconciled my mind to it. On the contrary, from day to day I had become more irritable at the sight, and my conscience swelled nightly within me at the thought that I had lacked the courage to protest. Again and again I had registered a vow that I should deliver my soul upon the subject, but there was that in the cool, nonchalant air of my companion which made him the last man with whom one would care to take anything approaching to a liberty. His great powers, his masterly manner, and the experience which I had had of his many extraordinary qualities, all made me diffident and backward in crossing him.

Yet upon that afternoon, whether it was the Beaune which I had taken with my lunch, or the additional exasperation produced by the extreme deliberation of his manner, I suddenly felt that I could hold out no longer.

“Which is it to-day?” I asked,–“morphine or cocaine?”

He raised his eyes languidly from the old black-letter volume which he had opened. “It is cocaine,” he said,–“a seven-per-cent. solution. Would you care to try it?”

“No, indeed,” I answered, brusquely. “My constitution has not got over the Afghan campaign yet. I cannot afford to throw any extra strain upon it.”

He smiled at my vehemence. “Perhaps you are right, Watson,” he said. “I suppose that its influence is physically a bad one. I find it, however, so transcendently stimulating and clarifying to the mind that its secondary action is a matter of small moment.”

“But consider!” I said, earnestly. “Count the cost! Your brain may, as you say, be roused and excited, but it is a pathological and morbid process, which involves increased tissue-change and may at last leave a permanent weakness. You know, too, what a black reaction comes upon you. Surely the game is hardly worth the candle. Why should you, for a mere passing pleasure, risk the loss of those great powers with which you have been endowed? Remember that I speak not only as one comrade to another, but as a medical man to one for whose constitution he is to some extent answerable.”

He did not seem offended. On the contrary, he put his finger-tips together and leaned his elbows on the arms of his chair, like one who has a relish for conversation.

“My mind,” he said, “rebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram or the most intricate analysis, and I am in my own proper atmosphere. I can dispense then with artificial stimulants. But I abhor the dull routine of existence. I crave for mental exaltation. That is why I have chosen my own particular profession,–or rather created it, for I am the only one in the world.”

“The only unofficial detective?” I said, raising my eyebrows.

“The only unofficial consulting detective,” he answered.