Audio Track Dropdown Menu

Name    Edit the name of the track Move Track Up/Down   Move Track Up or Down in the display Waveform   Traditional display of audio material. It displays the amplitude of the audio over time. This is the default display mode. Waveform (dB)   Like Waveform, it displays the amplitude of the audio over time, but here the vertical units are not linear, but logarithmic dB units. Spectrum   Displays the frequency spectrum of the audio over time. Pitch (EAC)   Tries to detect the pitch of the current audio and displays that information over time. Mono   Send playback of this single channel track to the left and right channels. Left Channel   Send playback of this single channel track to the left channel. Right Channel   Send playback of single channel track to the right channel. Make Stereo Track   The selected track and the track just beneath it are turned into linked stereo tracks, so that edits are applied synchronously to both tracks. Split Stereo Track   Turn one pair of stereo tracks into two single channel tracks, so they can be separately edited. Note that removing audio from one track will not shorten the other track: first apply Make Stereo Track to the pair if synchronicity is to be preserved. Set Sample Format   Change the sample format of this track. The result is that all newly written data for that track is written in this format, no matter what format the original material was in. Set Rate   Change the sample rate of this track. When importing audio, the track sample rate is set to that of the imported material. If your project rate is different, the audio will be automatically resampled to the project rate on playback or export. Changing the sample rate always changes the speed and pitch of the audio, so only use it for a special effect or if the audio sounds at the wrong speed and pitch.

Waveform

This first half of this waveform is a "Chirp" tone which stays at the same amplitude (loudness), as shown by the horizontal top and bottom. The linear scale on the left goes from +1 at the top (the maximum possible loudness without distortion when the signal is positive) to -1 at the bottom (the maximum when it is negative). The horizontal line centred on 0.0 is silence. What you can't see without zooming much further in is that the pitch of this tone is gradually increasing. Zooming would show the individual cycles in the waveform (the positive and negative peaks) occurring much closer together at the end of the sound. The second half of the waveform is the word "Audacity" spoken by a male voice.

This image is a waveform view of an extremely short chirp with only a few cycles, where the pitch increases very rapidly. As it's so short, we can zoom in to show the closer spacing of the cycles as the frequency (and hence the pitch) increases from left to right.

If possible, an image including the timeline would make the point even clearer (but not essential). However the zoomed in image is too wide. I think it could be the same length as the others while still getting the point across - Gale

Timeline doesn't always make the units clear - and having just redone them I don't fancy redoing the complete set again 'for comparison purposes', so a shorter chirp, yes, but probably without timeline.- James
OK, unless you think we can get away with the timeline just on the waveform images. Or we can just say how long the sound on the second image is - it probably is not obvious how short it is. Also you could probably resize the overlong image if you don't want to recapture it. Track Panel would be less wide but it would be obvious why.- Gale

Will recapture, with timeline.

Waveform (dB)

This is the same chirp and word as in the first Waveform image, but in this view the vertical scale is in dB. This is a logarithmic method of displaying the amplitude. It gives a better representation of the sound we hear, because this scaling gives better detail for the fainter sounds. It also shows more clearly than the waveform view how the energy of the "Audacity" word is naturally concentrated in the central "dac" part, and weakest at the end.

Spectrum

This view of the same chirp and word shows how the amount of energy in different frequency bands changes over time. Higher frequencies are at the top of the scale, lower frequencies at the bottom. The blue color is the least energy and the red and white are the most. The progressive increase of pitch in the chirp tone is vividly demonstrated by the upward sloping diagonal line. Spectrum view also confirms that the "Audacity" word has most energy in the middle of the word.

You can view a sound in Audacity in another way than over time. Here is the "Audacity" word again as a spectrum plot, showing the relative energy (dB) of each frequency in the entire word. Had the voice been female, the plot would have shown its higher frequencies.

Perhaps we should be using spectrogram and spectrum to differentiate between the two displays, and make a change in Audacity wording too? (not a high priority).

Not sure. I think the point about the spectrum plot might be to remark if it's made by a male or female voice (I presume that plot is yourself) and to explain what it might have looked like if a female voice had spoken it - Gale
We're already saying a bit more than we strictly need to for a reference on the features of the Audacity GUI. It's a good idea, but I think it belongs on a tutorial page, where we can show beat frequencies, clicks, hums, noise, spectrum of a square wave, flute vs guitar etc etc. Yes it's my voice.-James
If we ever produce such a tutorial, we can link to it here. Meantime , now we've gone this far, I've said it in about five more words than we had before. I also noticed we're missing what seems to me essential (what the waveform scales mean, which is not described elsewhere yet?). I've tried to work this in whilst taking only a few more words. This probably means we can now restrict Rulers to discussing the timeline. This makes more sense, and we can probably rename it to Timeline.
To me the current balance on this page is about right - I readily agreed with your idea of the example of the chirp and word here. Having only a strict "Reference" in the old manual was not popular - people wanted more explanation about what menu and Gui items meant and did and why, as well as the full blown tutorials on a complete process - see the Help list and old forum comments. -Gale

Agree strongly. This has become a very good page. I'll update the table to the file-menu look later.

There are several options for adjusting exactly how the spectrum is displayed.

Possibly add a link to part of some tutorial page describing how to track down clicks (using the spectrum view) and remove them. Maybe not in time for 1.4.0.

Pitch

ToDo This image needs explanatory text