Audio Quality Deteriorates With Each Revision

Dec 16, 2015

I develop courses that require many revisions and I've noticed that after a couple of revisions, the audio I've imported into the .story file will sound very compressed. If I have my voice talent record a new slide, for example, that audio will sound much cleared and closer to the source file.


My guess is that each time I save the file with a new name the audio gets re-encoded in a lossy format like MP3 and after a couple of saves it effects the audio fairly significantly (in my opinion at least). My workflow usually has me renaming the file with each revision, so that would make sense.


Any ideas how to better preserve the quality of the audio files I import into my courses?

23 Replies
David Jordan

Ah, understandable. I put narration in my slides and have similar situations. This issue is one i was unaware of (just switched to SL). 

Not sure how this will help older versions you have, but what i will be doing (if no other solution appears) is:

I will put my audio into several smaller files and have them un-cropped in SL. I will do the cutting and mixing outside SL.  I will sync my objects to the audio, never the audio to objects, unless i am moving the whole audio file along the timeline. 

I will do this so if need be, i could replace one bit of audio with an identical (but "older less compressed") version. and i wouldn't have to worry about it losing synchronization. 

Ashley Terwilliger-Pollard

Hi Parker,

I'm not sure this is something I've seen before and did a quick search and didn't come up with much. Are you able to share an initial audio file and then a sample of how it's changed once you do a save as? I think we would to have our team go through some testing on this and if you're starting out with some really high quality audio files it would be helpful to have one of those to start with. You can share here or you can send along to our team here directly. 

Parker D

Sorry about the delay. Here is an example of what I'm talking about:

This is the exact same slide with the same source file. The .story is attached if it makes a difference. The audio quality only gets worse the longer I work on a project and the more revisions the project has.

Christie Pollick

Hi, Parker -- no worries about the delay; we're always here when you're ready! Thanks for sharing your files, and we'll be sure to check them out shortly and let you know what we find. In the meantime, can you please take a look at this information on Unexpected or Erratic Behavior in SL2, and let us know if you find improvement after running through the repair steps listed in #2? 

Christie Pollick

Hi, Parker -- Thanks again for your patience! Unfortunately, I am not having any luck with audio improvement after reimporting the audio file you provided (no discernible difference), so at this point, I think it would be best to refer you to our Support Engineers for further investigation. I'm sorry that I don't have your last name here so that I can look you up in our ticketing system and create a support ticket on your behalf, but please use this form to submit your case, and I will be sure to follow along with their progress. :)

C. L. Norman

I’m experiencing this issue, but it involves image quality deteriorating after multiple revisions.  The source files are in both lossy and lossless formats (mostly PNG, TIFF, and JPEG), and the one I noted today was a TIFF I had to retouch in Adobe Photoshop.  It was clean and pretty when first replaced, but now it bears obvious quality loss that is consistent with what I’ve seen when  people save JPEG files repeatedly.

SL2 isn’t somehow “recycling” these images, is it?  If it is recompressing using lossy compression each time, that could be a problem.

Christie Pollick

Hi, C.L. -- So sorry to hear of your difficulties and thanks for reaching out here! You may want to take a look at this thread over here on a similar topic and let us know if the suggestions offered help you find improvement. Or, you are welcome to share an example of the behavior you are experiencing so we are better able to assist you. :)

Leslie McKerchie

Hi Byron!

I'm not sure if Parker ever submitted a support case, so I do not have an update to provide on that.

You are welcome to work with our team here.

When you record narration in Articulate Storyline, MP3 files are generated with an audio bitrate of 192 kbps, and they're stored in your project file. When you publish your course, the audio files get re-encoded at the bitrate of your choice. See this article for details.

Byron Jones

Hi Leslie,

Actually this issue happens BEFORE even getting to the publishing stage. It happens even in preview of the course after editing an audio file. 

All of my audio files begin at 320 kbps -- in an effort to keep quality high from the start.

And the odd thing, is that MIXED audio qualities exist in the same SL file. Meaning, you insert a high quality audio file, edit a piece of it (say: delete a piece of audio from a single file, save it) and instantly that audio becomes a lower-quality file in your project.

Question is:  Why should this happen? and happen consistently without fail?

So the issue is a simple one:  Editing a high quality piece of audio in Storyline causes that individual, edited file to reduce in quality/bitrate. It's certainly a bug.

The only workaround is to jump out of the program, create a new audio file in another application (a new chunk of audio, bypassing SL audio editor) and inserting that new piece in the course. It's a clumsy way to have to juggle audio, but to have a quality-consistent audio stream, it's a necessity.

If there's no immediate solution, I'll file a case w/ tech support.




Joseph Ferraro

I'm late to this party, but for what it's worth, I've absolutely noticed this issue too.

I can confirm that I can import a 44.1khz 16bit .wav that sounds great, edit it to crop some noise or whatever, and as soon as I save that, it gets encoded as MP3 and the quality on preview is (unsurprisingly) significantly reduced. It gets worse after publish due to the low-kbps audio quality choices. Maxing out at 160 kbps is really unfortunate.

I'll add as well that the same is true for videos that you do not set compression to "None" on, so make sure as soon as you import videos to turn off that automatic compression setting to prevent it from making that audio murky.

Joseph Ferraro

Just wanted to follow up on thread - Support has confirmed that editing audio in SL2 will apply encoding compression based on the publish settings. This seems to mean that after publish, that audio will have been encoded twice, and the end result will likely be artifacts related to the lossy nature of the mp3 encoding process. Best solution is to edit outside of SL2 then re-import.

Another item for the SL3 wishlist :)

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