Editing 64k mono iPod Recordings (AAC/M4A) with a PC

You can record with the voice memo feature (default ipod app). It’s AAC, a compressed format. But converting it properly (not decompressing) is impossible (I guess) if you want to edit it with Audacity or whatever. The way I’m doing it currently is running a line out of my ipod headphone jack into my computers line-in jack in the back then re-recording it with Audacity. Not sure if this is best but so far it seems the best way other than not editing it and just leaving it as AAC/M4A which can not be edited as far as I’ve found beyond using mp3gain to adjust volume.

You should be able to export a .wav file from the .aac from iTunes, then edit in Audacity as normal.

Getting iTunes to offer the option of converting to .wav is not obvious (as I had to do it recently). What you have to do is under “preferences” → “general” there is a button labeled “Import settings” in the section related to importing CDs. If you click that and set “Import using” to “WAV encoder” you will then be able to right-click the recording and say “Convert to wav”.

Yes. iTunes format conversion is an import feature, not an export feature. Wasn’t that fun?

AAC/M4A which can not be edited as far as I’ve found beyond using mp3gain to adjust volume.

Upconverting to a higher quality sound format generally gives you a really accurate AAC or MP3 damaged WAV sound file. If you make a new MP3 or AAC after Audacity editing, you’re still going to get multiple compression sound damage.

The video people once claimed a partial reversal of MP3 damage, but I suspect they were hiding the damage better rather than returning the original sound quality.

I’m sorry to hear about the forced compression in the iPod sound capture. Several people have reported that. I had hoped to use one as original sound capture for a production. “Drop your studio in your pocket.”

It seems dragging along the bottom of sound capture equipment is only giving me bloody knuckles.


There is one partial way around this. If you export your Audacity work as WAV or very high quality MP3 (or AAC), that export won’t get worse.

But that can get you stealth compression problems later. We had one poster delivering reasonable quality music shows to a radio station from MP3 music downloads. Everything was more or less OK until the station tried to post the show as a compressed podcast.

Sound went straight into the toilet/loo.

His posting was: “How to I prevent that?”

Stop using MP3/AAC compressed work in your shows.


64k bits/second is actually a pretty good data rate for a mono 44.1 kHz file… Surprisingly high given that the feature is labeled “Voice Memo” I would have expected no more than “telephone quality”. That works out to 11:1 compression. I suspect that there will be more flaws in the recording due to the tiny MEMS microphones in the IPOD (assuming you have one of the newer ones) than from the compression, and certainly converting the file directly to wav in iTunes will have fewer issues than converting to analog and then back to digital as Black Dog is doing now.

I did a quick search and did turn up a number of iOS apps that claim to do uncompressed recordings so it is possible.

Good to know. I was planning on an external higher quality microphone, not the built-in one (my retarded iPod doesn’t have a built-in one. It may even be too old to accept sound APPs).

Many people bump into 32 as the lowest possible quality for mono recording. 64 is a significant step up, although I don’t know that I’d want to sing into that.


ha–ha great info guys… I do know about the iTunes ability to convert but as Koz states–still not good idea–but as ‘fly’ states possibily better than re-recording line-in------------------? yeah maybe/not sure, may experiment again but previous experiments of ‘up’ converting/were failing for me in comparison to just leaving it as AAC/M4A (and then using mp3gain[modified for AAC] to adjust volume as needed, even allowing clipping on some songs–to a point)–but maybe iTunes does a better [up]convert–?/I doubt it though. Will post if so. And yes there are apps! But I do not like the way Apple wants me to dance to get one–so I have avoided their ‘app-world’ --and yes you can even buy a better mic that attaches to the main ipod port/which probably requires an app as well. Other than that–I would just buy a portable MUSIC-designed recorder when edging up to the 100 dollar range!

PS I am not happy with the re-recording (from ipod voice memo) line-in quality either-------I was hoping but–don’t think it’s better than just leaving these as they come–AAC/M4a’s. I started this thinking after hooking my cassette deck up–line-in and recording (with Audacity) a little of a cassette–and it sounded pretty good–but I guess there is loss going on there as well–but with a good cassette and player to start with I assume the end result (although lessened in quality) is not so bad–compared to the already poor sounding 64k voice memo recordings (lessened per re-recording). Or as ‘fly’ mentioned, it’s the digital to mono to digital[?] versus with cassettes just mono to digital[?] transfer being the[this] difference[?]. :unamused:

Where does it say your iPod has a Stereo Line-In? Mine has a “headset” connection which is stereo headphones and a single mono microphone. Microphone sound level is stunningly lower than the output of a cassette machine and you are likely to create overload damage.

There is a similar problem with Windows laptops.


Unfortunately the term “compression” has multiple meanings in this context, and I suspect that both might be apropos. There is bit-rate reduction – the thing inherent in the AAC files that involves throwing away some of the information about the sound waves that your ears generally don’t notice Then there is dynamic-range compression – what the various “compressor” filters in audacity do – examine the waveform and ride the gain so that there is less difference between the quiet bits and the loud ones. Since the “Voice Memo” feature is intended for just that I wouldn’t be at all surprised if there was some dynamic range compression happening as well.

In any event, all the damage is done in the creation of the AAC. There is no further damage in creating a un-compressed (in the former sense) WAV file from the AAC, the resulting WAV file should sound exactly the same as the AAC. The reason everyone recommends NOT using a data-compressed format like AAC or MP3 for production is that repeated application of the data-compression will result in the errors introduced by the data compression accumulating and becoming more and more audible.

There are also errors introduced anytime you convert back and forth between digital and analog. The gain will always be slightly off, analog noise will be added, unneeded anti-aliasing filtering will be applied, and likely small amounts of distortion. Repeat that process enough times and the errors will become audible as well. This why I assert that you’re better off asking iTunes to convert the AAC to WAV for you.

Well now must conclude iTunes created wave is the best way to get the most out of these with the help of Audacity-- I used noise removal (at settings: 48, 0, 500, and 1 attack). Not sure if using the full 1 second option for attack/release was best but it seemed okay, may try less next time but previous “.01” attempts/the other extreme, never worked right/ this time I intensely read the help… and then used SC4 (using Geoff’s recommendations[partially]/see youtube vid: https://www.youtube.com/watch?v=lcEQJBO1Kj0 Also used his recommended W1 Limiter plugin) And then I custom manually damped (de-amped) still obtrusive peaks and fixed other little defects as best I could. Here is the iPod recorded, iTunes to WAV conversion, Audacity edited (exported 320k MP3): “Flowers Mean Nothing” LINK/SONG GONE/new here (with Tascam dr-05): https://soundcloud.com/blackdog2016