Sound vanishes during recording

Hello, I am new to the forum and very much appreciate any help on what’s happening when I record.

I have Audacity version 2.0.3 and my operating system is Windows 7. The computer I use for recording is new, purchased within the year and has a very large hard drive so I don’t believe disc space could be causing this. It would probably help to let you know that what I use Audacity for is not what most people probably use it for. I work in education and I record presentations, which I format into E-Learning courses. Most of the presentations we record using Audacity are 1/2 or 1 hour long. Some are more. Please also excuse my lack of technical recording terminology & knowledge, I have not received any formal training in recording, etc. I’ve been using Audacity for about 2 years now for this and the problem only came up recently.

Inthe last 2 months, I have experienced a strange glitch with Audacity when recording, and I am hoping someone else may have experience with how to fix it. When recording, the microphone is working correctly and I see the line change from flat when my presenters speak. On a couple recordings, after completing the hour-long presentation and then viewing the whole file, the audio from the majority of the presentation has changed to a flat line. (I watch the audio as it records because part of what I have to do involves noting times of certain parts of the recording for formatting of the education from the audio.) For some reason, it only kept the audio for about the last 5 minutes of the presentation. (I ended up having the presenter re-record the first time this happened.) I can upload a short sample of when the audio cut off it anyone with experience may be able to explain what happened.

Since the first time this happend, I created a sort-of back-up method. I have downloaded Audacity onto one of our laptops that has a built-in microphone and I set it up in the same room and make 2 recordings, and the error has not happened on both computers at the same time yet. However, I am hoping for a better solution than setting up two computers to record.

But it happens on both computers?

I like to change the Audacity default presentation by making the bouncing sound meters much larger. They’re very much more important than you would believe by the tiny default size. Click on the right edge of the meters and pull to the right. The meters will get bigger and easier to see.

To summarize, you see the bouncing red sound meter and the blue waves are assembling themselves as you go, but when you go back and review the whole show, Stop and Control-F, portions, or sometimes most of the show has reverted to flat lines? If you play the flat lines, they’re completely silent?

Drag-select a small portion of one of the flat lines and Effect > Amplify. Read the top number.

Audacity > Edit > Preferences > Interface. Read the Meter/Waveform dB Range.

It happens at random on two different computers? Is there any two-month old event at all? You installed Skype? You did a Flash upgrade?

Is there any correlation at all? Only a certain speaker fails? It fails on sunny days? Only shows of a certain length?

Are the computers connected to a network and do you keep the virus protection up to date?


One more. The show is the right length? If you record an hour, you get an hour show, but portions are silent?

Koz -
Thank you! I really appreciate any assistance that can be provided. I am far from an expert, I learned the basics of Audacity from notes left by my predecessor here and then learned more on my own by experimenting with what the features do.
I’ll try to answer all of the questions…

It has not yet happened on the laptop but has happened multiple times on the desktop, both on the previous PC and the new one we got recently.

When I record, the sound meters are going and the blue lines appear, but when I look at the whole presentation - there’s a flat line where the blue wavy line used to be for most of the presentation.

I tried to amplify the flat area and the speaker was still gone.

This “Audacity > Edit > Preferences > Interface. Read the Meter/Waveform dB Range.” I have not tried yet… I’m not really a sound expert so I have not used many of the features or changed much of the settings.

It has happened randomly on the desktop PC, both the current one and the previous desktop PC. It’s not through Skype or flash, we are pretty low-tech - our speakers actually call in by telephone and our microphone is positioned to record via speaker phone. (we are looking into other options but this is what we do now.)

I have not noticed any particular speakers or time of day or anything that match up. Sometimes the recordings that fail are a single speaker calling in, sometimes they are are a presenter with an audience, who have the ability to comment and add to the presentation (all from their own phones on our conference call line.)

The desktop computer is on our network with up-to-date virus protection, the laptop is off of the network and also has up-to-date virus protection. Our IT company takes care of them and ensures they are always updated.

The audio does end up the correct length - one in particular was about 55 minutes of silence followed by about 5 minutes of the speaker when I was done recording - even though she spoke for the entire hour.

Ensure that Audacity is installed locally on the computer and that you’re not attempting to run it across the network.
Also check that the Audacity temporary folder is on the local drive and is not a network drive (Edit > Preferences > Directories) - get your IT guys to help with that if necessary - the Audacity tmp folder must be accessible or the recorded data will just “disappear”.

Thank you!
I installed Audacity on the hard drive of the computer - I believe that is where the temporary folder is located. I will ask our IT to check on that though. We use the hard drive rather than the network drive for the E-Learning programs because the other software we use also does not generally cooperate with network use.

In addition to that computer, once I save my files, I do export them to the network drive. Then, I open the WAV files from the network drive using Audacity at my 2nd desktop computer (which I didn’t mention previously) and it seems to work ok on that PC. Audacity is installed on the hard drive on all 3 computers I use it on.

One computer is for recording - because it’s in a room with a door that locks/closes and generally keeps noise out. That’s the one (so far) that has made the sound vanish. I use the PC at my normal desk for editing, and I use the laptop for a back-up recording.