Hi Tricia—I am uploading this recording in the hope that I might get some feedback on the problem, which I have had repeatedly, of the crackling that begins at about 3:28 and continues through the rest of the recording (notice that it happens with my voice, not in the silences).
I intend to re-record it, but I'm hoping you or someone else might be able to identify the problem. I have had to re-record most of the files I've submitted several times because of this phenomenon. I have not been able to identify any external cause for it, and only become of aware of it on playback. We have had some thunderstorms lately, and I've wondered whether it might be caused by atmospheric disturbance, but there was no electrical storm activity yesterday when I recorded this. So far, it seems to be entirely random, and sometimes I make it clear through a reading with no disturbance, sometimes not. I try to make sure my AC and refrigerator are not on, but that does not seem to be the problem, as I've made good recordings with both of these running, and bad ones when they were not. If you or someone at Librivox, recognizes this problem and can shed some light on how it can be avoided, that would be great. Otherwise, I'll just keep trying till I get a clean copy.
A mystery, certainly. The irregularity of it suggests a software problem, not interference. And when I say a software problem, I'm thinking buffer overrun/overflow, or some dynamic effect on, or simply a bug in the driver. The usual boilerplate advice - check the effects and turn them off (like AGC, noise reduction), check for a newer version of the driver and update.
tovarisch
reality prompts me to scale down my reading, sorry to say to PLers: do correct my pronunciation please
Thanks, tovarisch—I'm running audacity 2.2.2, recording on my early 2011 MacBook Pro (17") with only built-in input/output. I'm a complete novice at this, I'm not quite sure what the gain control does (I have it set at zero, which has mostly seemed to work OK), if there's an automatic gain control, I don't know where to find it. Buffer overrun/overflow? I googled it, but what I've found so far is only confusing to this non-tech.
Thanks again for your input and any further help you can offer.
Is there anything running on your computer in the background that could account for the intermittant appearance ? I know I had problems with virus checks starting at one stage. Though it did appear to make the recording drop off bits, which is different. Maybe worth trying to see whaat else the computer is doing though - it's a cheap and easy solution if it works.
Does it always appear and then remain , or does it come and go in the same session
deakle wrote: ↑July 22nd, 2018, 6:51 pm
Thanks, tovarisch—I'm running audacity 2.2.2, recording on my early 2011 MacBook Pro (17") with only built-in input/output. I'm a complete novice at this, I'm not quite sure what the gain control does (I have it set at zero, which has mostly seemed to work OK), if there's an automatic gain control, I don't know where to find it. [...]
Hi David,
I am not very proficient in on MacOS, sorry. There is one place where you should go to check for the Automatic Gain Control - the system preferences for sound. There should be several pages of controls and some of them are dedicated to the "input" (rather than output). Look at each for a checkbox titled "AGC" or something of that kind. It's quite possible that yours will not have AGC, but there can be other controls to try.
As far as setting your gain at zero in Audacity - that is suspicious and is another reason to find and turn off AGC or other special features.
tovarisch
reality prompts me to scale down my reading, sorry to say to PLers: do correct my pronunciation please
Thanks, Annise, I'll check this out. —Yes, so far any time it's appeared, it's remained to the end. Appears at some random point—sometimes near the beginning sometimes near the end (or anywhere in between) of the recording.
Two possible sources for intermittent noise on your MacBook Pro are the hard drive (unless it's a solid state drive) and the cooling fan(s). Since your build in mic is omnidirectional and mounted in the computer case, it's in a perfect place to pick up mechanical noise from the computer itself. If you can borrow an external mic to plug into the mic input, you could see if this reduces or eliminates your noise.
Hope this helps.
Winston
Be kind. Be interesting. Be useful. Morality ain't hard.--Jack Butler, Living in Little Rock with Miss Little Rock
A mystery, certainly. The irregularity of it suggests a software problem, not interference. And when I say a software problem, I'm thinking buffer overrun/overflow, or some dynamic effect on, or simply a bug in the driver. The usual boilerplate advice - check the effects and turn them off (like AGC, noise reduction), check for a newer version of the driver and update.