I have created a lovely little pod cast, speach, music. SFX. All is well, it sounds good, everything is saved.
Then I go to give the piece a final review and whole sections of audio have just disappeared! I can see the wave form on screen, i can highlight it and even move it, but I hear only silence. What has happened? Can I reverse this?!
Help!
Have a look at this page:
http://manual.audacityteam.org/index.php?title=Import_/_Export_Preferences
It sounds like you’ve moved or trashed some of the original sound files you imported into the project, and that Audacity was set to NOT make copies of uncompressed files on import.
This has been known to bite many users. It’s especially confusing since the blue waveform is still there, even though the audio file that it represents is gone.
If this is the case, and you still have the original files, move them back to their original locations and open the project. If you get your audio back, go to Preferences > Import/Export and select “Always copy all audio into project (safest)” under “When saving a project that depends on other audio files”. Click OK to save the new preferences, then click on File > Save Project As and save it with a new name (just to be ultra-safe).
Hope this helps. Please let us know if this fixes your problem.
– Bill
Thanks Bill,
I have not moved or deleted any of the files, they still exist in their original location. Also, some of the files partially play before cutting out. It worked fine last night and today… it’s half gone. I guess I am going to have to build it again - ouch! In the meanwhile I will do as you suggest with the preferences.
Thank you for a promt reply and the link - now where can I find a strong coffee to get me through the rebuild?!
Ahh in fact I did move some files, I had been tidying up! Thanks, its worked a treat and everything is restored. I shall amend as suggested.
Thanks again for the help Bill.
Glad it worked. No need for strong coffee 
Also, go to Audacity Preferences > Import/Export and under “When importing audio files” check “Make a copy of uncompressed audio files before editing (safest)”. Then you’ll never have this problem again.
– Bill
Where do the sound files go when you tell Audacity to copy them into itself?
Koz
They go into the _data folder as .au files.
If you import without copying, Audacity creates a bunch of .auf files that do not contain audio, and this shows up in the .aup file:
<waveclip offset="0.00000000">
<sequence maxsamples="524288" sampleformat="131073" numsamples="15249192">
<waveblock start="0">
<pcmaliasblockfile summaryfile="e0000495.auf" aliasfile="/Path/to/audiofile.aiff" aliasstart="0" aliaslen="524288" aliaschannel="0" min="-0.501923" max="0.481445" rms="0.102337"/>
</waveblock>
<waveblock start="524288">
<pcmaliasblockfile summaryfile="e0000856.auf" aliasfile="/Path/to/audiofile.aiff" aliasstart="524288" aliaslen="524288" aliaschannel="0" min="-0.927032" max="0.864258" rms="0.139328"/>
</waveblock>
These .auf files are about 24K in size.
If you then edit the track (say, cut out a few seconds), Audacity creates .au files (containing audio) to cover the edit, but still maintains the .auf files for the portion of the original file that has not been edited. The .aup file changes to look like this:
<waveclip offset="0.00000000">
<sequence maxsamples="524288" sampleformat="131073" numsamples="15181774">
<waveblock start="0">
<simpleblockfile filename="e0000b41.au" len="456870" min="-0.501923" max="0.481445" rms="0.107819"/>
</waveblock>
<waveblock start="456870">
<pcmaliasblockfile summaryfile="e0000cda.auf" aliasfile="/Path/to/audiofile.aiff" aliasstart="524288" aliaslen="524288" aliaschannel="0" min="-0.927032" max="0.864258" rms="0.139328"/>
</waveblock>
If you start over and set Preferences to copy imported files into Audacity, then Audacity creates a bunch of .au files (containing audio) that cover the entire original file. Each waveblock contains a simpleblockfile.
– Bill
It looks like the Preferences dialog has changed in 1.3.9 versus what is in the manual. The above preference is now under the Projects tab.
– Bill
Importing the audio is the default, now, right? So we don’t have to constantly answer the same question again and again and again…
Koz
We can only hope.
– Bill