At this point, it’s important to note the difference between a podcast and an audio course and the lessons that make up an audio course. Podcasts serve many purposes: daily news, talk shows, short and long form interviews. Even great educational podcasts like ‘Invest like the best’ and ‘Let’s know things’ take on these characteristics. Because of these different purposes, podcasts vary greatly in length: they have to introduce the speakers, give background on a topic and try and dive deeply into it. There are many forcing functions to the length of your podcast.
When it comes to an audio course the question is different. It’s less a function of how long your podcast has to be to achieve your goal. Rather it’s a choice of how long your lesson should be to make your audio course the best.
The two factors that impact your lesson length
Two factors impact the length of your educational podcast/lessons:
But it’s more than just repetition. You need to structure your lessons properly: an interesting introduction, the topic you’ll learn and a good summary. Additionally, to make your audio course really work, you’ll need to layer in concepts of what you learned in previous lessons.
What this means is that three to five minutes is simply not enough. In fact, this usually takes at least 12–15 minutes. So the minimum length should be 12–15 minutes, but often topics, especially complex ones can take longer, so how long should you go? This is where the second factor comes into play. Interest.
Interest is a very vague category, since some podcasts like Dan Carlin’s Hardcore History are incredibly long (incredibly long — 4 hours long) and yet still hold the audience’s interest. On the other hand, many podcasts are unnecessarily lengthy and would be well serviced by good editing. So in some senses, length based on interest is arbitrary. However, when it comes to an audio course, a good rule of thumb to follow is an average of 20 minutes per lesson. 20 minutes is long enough to cover most topics, and yet it forces the brevity required to keep things interesting and moving. Better yet, the average commute length is roughly 25 minutes, so 20 minutes is exactly the length that will accompany your learners on the way to work.