iPod 4G Audio Defect: The Details and Test | iLounge Article


iPod 4G Audio Defect: The Details and Test

This page is a central hub summarizing known information on an audio defect affecting certain fourth-generation (4G) iPods. Our previous news stories on the topic are available here, here, and here.

What is the Audio Defect: “Users of affected iPods will be able to hear a hard disk-like whirring sound in their earphones, coupled with several seconds of light static at the start of a song that has just been loaded. This should not be confused with the quiet hard disk loading sounds that an iPod makes, which sounds are not audible through earphones, or with normal static-like compression artifacts in your audio.”

Who is affected by the Audio Defect: iLounge initially believed that the Audio Defect was limited to a small number of units, perhaps only 40GB iPods, as three of iLounge’s four total 40GB test units have now exhibited the problem. However, user comments subsequently established that both 20GB and 40GB units are affected. The exact number of problem units is not known, or for that matter knowable. iLounge has been gathering user input for three weeks, and emphasized “that [while] the results of our inquiry are comprised of strictly voluntary submissions from readers, and should not be taken as scientific or conclusive, they do suggest that the problem may be more widespread than we had originally hoped.” The most recent requests for positive or negative test results have yielded hundreds of responses from users around the world. Approximately 42% of responding iLounge users reported the audio defect in one or more of the 4G iPods they purchased or received in exchange.

How can you test a 4G iPod for the Audio Defect: “To test your iPod while eliminating the possibility that static from your music or headphones may be responsible, use iTunes to encode several three- to five-minute compact disc tracks using Apple’s Lossless Audio encoder, transfer them to your iPod, then connect the earbuds packaged with your new iPod. Find the directory or create a playlist with only the Lossless tracks, and skip back and forth between them. Hold your iPod at a distance or cover it up so that you can’t hear its normal internal hard disk sounds. If your iPod has a problem, at the start of each loaded song, you should hear a loading pause, then a whirring sound and light static in your ears at a normal volume level. If it does not have a problem, the song should load and play without audio interference.”

Common misconceptions regarding the Audio Defect:

  1. The problem is not caused by Apple Lossless encoding. iLounge’s testing procedure recommends Apple Lossless solely because large file sizes cause more frequent accesses to the iPod’s hard drive, therefore more quickly revealing the problem on an affected iPod.
  2. The problem is not caused by Chinese manufacturing per se. iLounge posted details regarding its test units (shipped from Shanghai, China) in an effort to help Apple and possibly affected users identify a specific plant from which affected units were being produced.
  3. The problem is not limited to orders coming from the Apple Store or to the United States. Issues have been reported in 4G iPods purchased from different stores in different countries.
  4. The problem is not the same in all affected iPods. iLounge has now heard affected iPods where the noise is only audible in one of the two headphones, and others where it is audible in both headphones at once. Some affected iPods appear to make the sounds loudly, while others appear to be more mild.
  5. The problem is not identical to problems in prior-generation iPods. Some users of older third-generation iPods and iPod minis have reported similar sounds that appear only when charging and using accessories connected to the Dock Connector port. The current problem manifests when the iPod is not connected to any additional hardware save headphones, and typically can be heard overlapping the music with static.
  6. The problem does not exist in a unit just because it makes hard disk access noises. Every iPod contains a hard disk that loads data in chunks during playback, and this hard disk is not supposed to be silent - but you shouldn’t generally hear it inside your headphones. Hard disk access noises coming from the iPod’s case (and audible without using headphones) are totally normal. The Audio Defect only exists when you can heard the sound of hard disk accesses accompanied by static coming through the headphones attached to the iPod. Some users have reported that audio played through the Dock Connector port exhibits the same issues.
  7. Added Aug. 23, 2004: The iPod’s part numbers are of no aid in sorting problem units from non-problem ones. Apple’s two current model units (M9282LL/A - 20GB, M9268LL/A - 40GB) are uniformly identified by these part numbers, and contrary to rumors that have been floating around, to the best of iLounge’s knowledge there is no “fixed” M9282LL/C or M9268LL/C version of either product.

What is Apple’s official position on the Audio Defect? (Updated 9-17-04) We have continued to request comment from Apple regarding the Audio Defect, and in response to a September 16 inquiry, an Apple iPod team representative responded on September 17, 2004 that “Apple does not have any comment at this time.” We had previously noted that Apple had not commented on the record to iLounge since late July, at which time the company indicated that it was still looking into the issue. Some users whose units exhibited the problem have reported receiving exchanges from Apple Store locations and certain other Apple-authorized retailers.

What is iLounge’s position on the Audio Defect? Our concern is first and foremost for our readers, and we take pains to promote iPods and related products that provide the most trouble-free and positive experiences for our readers. iLounge informed Apple Computer of its findings immediately after discovery in an effort to minimize the Defect’s impact upon iPod users, and provided its own affected units to Apple for testing. In the absence of further official comment from Apple, iLounge continues to consider this issue a serious one, and thereby reluctantly but strongly cautions its readers to purchase their 4G iPods only from retailers with complete return policies, or to hold off on 4G iPod purchases until Apple confirms that the issues are being addressed.

Is there a fix for the Audio Defect? (updated 11-1-04) As pointed out in early October by reader Jeff L. (and reported in iLounge Backstage), an almost identical problem was identified by Rio, makers of the Carbon audio player, which agreed to alter its manufacturing processes to eliminate the problem in their hardware altogether. We believe that this is the most appropriate course of action, as it requires owners to expend the least effort themselves to get fully working hardware. iLounge users have recently reported that they have returned 4G iPod units to Apple for repair and received fully working units in exchange, indicating that Apple is capable of diagnosing and remedying the problem. As a temporary solution for users who are not as concerned about the cosmetic appearance of their iPods, some users have reduced Audio Defect-related noises by placing a piece of tape or plastic between the iPod’s headphone port and the flat metal edge of the headphones’ plug, preventing any metal-on-metal contact other than the tip of the headphone plug. Thanks to JC and others in the thread for pointing this out.

Are there any updates on the Audio Defect? (updated 11-1-04) None officially through Apple. As iLounge has previously reported, a similar (albeit quieter, in our testing to date) defect appears to exist in the new iPod Photo, as well.

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I’m on my 3rd 60GB photo since Christmas…  The third one is the worst so far, the noise has a much higher pitch to it on this one.  There’s no way to miss it.  The other 2 ones I tried were pretty much the same (always right ear only, just not has high pitched as this model).

I’ve found out a few interesting things…  The noise does not happen with every song.  I’ve tested this with a few songs that are relatively quite and I can’t get it to happen on some of the songs.  Other songs, I can get it to occur 90% of the time, just by switching back and forth between tracks (e.g. most of the songs in the album ‘20’ from Harry Connick Jr. and The Cello Suites from Yo-Yo ma).

The other important thing to know is that the noise does not just occur at the beginning of songs (a few have posted this result).  I hear it in the middle of songs, even songs that are not quiet.  It probably happens every 30-50 secs, but is not as long as the first read at the beginning of the track. 

This occurs with every type of headphone I’ve tried, but is more noticable on higher quality phones (like my Sennheisers).  The ear buds that come with the Ipod are seriously restricted in the upper frequencies, which makes it harder to hear the defect, but it is there. 

All of my music is 320 AAC, so it doesn’t need to be lossless.

I’ve tried eliminating metal/metal contact as well as not allowing the plug to be inserted all the way (via numerous different methods).

I’m able to listen to the Ipod about 6 hours per day while I work and really enjoy it.  I just find the noise in the middle of the song far to distracting.  If it was only at the beginning of the song I could live with it.  I’m going to try 1 more unit, and if it still has the problem, then I’m done with Apple. 

If this is as good as it gets, then the Ipod is FAR from a product that an Audiophile can enjoy.  It’s just too distracting.  Although I’m an Audiophile who normally enjoys music for it’s own qualities (i.e. regardless of system limitations) I find this defect has got me on edge and distracts from my enjoyment.  I’m hopeful that the next one will be THE ONE…  Aside from this glaring flaw, I really love this little unit.

Posted by RIpod on January 28, 2005 at 2:14 PM (CST)


Just another note that I forgot to mention in the previous post.  The harddrive whirring noise is seems to have a fixed level, if you turn up the volume on the Ipod the whirring noise is not louder…  If you are testing for the noise, don’t turn the volume up too loud.  My normal listening position is around 1/3rd..

This has me thinking that a headphone with a low sensitivity might perform better with the Ipod photo.  This could be why it isn’t as noticable on some headphones.  I haven’t been able to eliminate it with the ones I’ve tried though.

Posted by RIpod on January 28, 2005 at 2:39 PM (CST)



i don’t own an iPod but I experienced the problem in a store and a friend of mine owns an iPod with the same problem.

I tried to figure out what may cause the problem and I do think that the problem may come from the power supply (rechargeable battery)

I have a HD-based VCR (something like TiVo I think) with the same problem, everytime the HD spins up, it sucks all the power and the picture fades away. So this problem may be caused by hard drives which suck too much power.

I cannot prove anything but as everyone says that the problem only occurs when the HD is being accessed this is ONE possible reason for the problem, although it is also bad news, because you can’t replace the HD or the rechargeable battery pack. :-(

Posted by Michael Adams on January 29, 2005 at 11:27 AM (CST)


I have the U2 ipod and i’ve found that I don’t have the defect when using headphones, reguarless of the kind of headphones. However, when I use my Griffen Itrip, I do get about 3-4 seconds of static when the hard drive is spinning.  Could it have something to do with the 4 pin remote control plug?

Posted by matt928347 in California on February 8, 2005 at 11:00 PM (CST)


Just bought my 4G 20Gb iPod today, accompanied by much fear that I would have to return a defected one. I had no defect whatsoever, much to my joy. AndI love this device already!

Posted by Chonny in UT, USA on February 11, 2005 at 10:38 PM (CST)


seems like I don’t have this audio defect in my unit, YET. just yet. but will see if this develops in the future.


Posted by narjisse in NY on February 27, 2005 at 9:10 AM (CST)


defect found on 4g 40G photo.
it happens not only when apple lossless but mp3’s as well

Posted by narjisse in NY on March 7, 2005 at 1:29 PM (CST)


audio defect found on my replacement 4g 40G photo as well.

So, 100% (2 out of 2) defective rate on my iPod photo 40 GB purchase. darn it.

Posted by narjisse in NY on March 16, 2005 at 4:27 PM (CST)


I have the ipod U2 edition.
Didn’t have this problem.

Posted by rolin in Malaysia on April 5, 2005 at 10:27 PM (CDT)


For any further posts regarding this issue:
When your iPod is purchased and registered online, there is a one-year warranty. Using Apple’s online support system, go to http://depot.info.apple.com after having registered. You simply input some information, shipping address, purchase date (does not have to be precise), problem with iPod etc. and Apple will shortly send you a box in which to send Apple your iPod. Apple will then ship you either your old iPod repaired, or if they can’t fix it in approximately 30 seconds, they will ship you a brand new one. Shipping and handling are covered for the first six months of the warranty; after that, you are responsible for paying for that. As well, if Apple does not have stock of your iPod, they will send you the next best iPod they have in stock. By the way, those of you who are scared to part with their iPods (I was)... I requested the box on a Friday morning, the box came Monday, I shipped it out that day, on Tuesday my brand new iPod came back. As well, assuming you got your iPod engraved at Apple, it will be kept.

Posted by benjs on April 6, 2005 at 6:42 PM (CDT)


I briefly skipped through this entire posting, but here goes on what I found:

I have a 40gb ipod 4G.  I performed my test using an aftermarket set of headphones with a metal base.  With the headphones plugged in I rapidly pressed the next track selection button several times.  While holding the ipod I can feel the hard drive being accessed from the rapid advancing.  The 192k mp3 song begins to play with no audible flaws!  I repeated this going back and forth through the same album and all is ok.  I performed the test again, but this time I put slight pressure on the headphone connector so that it was being pushed away from me slightly.  Now when I rapidly advance several tracks I feel the hard drive kick in and then as the song begins to play there is the audible static sound.  It was repeatable as long as I put pressure on the headphone jack.  So my guess would be that this has the same problem my rio carbon had with the headphones touching the metal case and shorting out.  I just took a piece of black electrical tape and made a small hole for the headphone tip to protrude through.  I think the ideal fix would be something like a page saver disc (for loose leaf paper) to stick onto the ipods metal case to isolate the headphones from the case.  Anyone know of smaller page saver discs?


Posted by mavrim on April 22, 2005 at 8:59 PM (CDT)

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