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 the waveform in this image shows a "Chirp" tone which stays at the same volume but gradually rises in pitch. You can only see the pitch change on a waveform display by zooming in much further. This would then show the individual cycles in the waveform (the peaks near the top and bottom of the scale) occurring much closer together at the end of the sound. The second half of the waveform is the word "Audacity" spoken aloud.

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.

Tried to shorten explanation of cycles and zooming as it was a bit repetitive.
Yes - improved.

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.

Waveform (dB)

This image shows the same waveform, but this time with a logarithmic method for displaying the amplitude (loudness) on the vertical scale to left of the track. This gives a better representation of the sound we hear, because the logarithmic 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 displays how the amount of energy in different frequency bands changes over time. Higher frequencies are towards the top, lower frequencies towards the bottom. The blue color is the least energy and the red and white are the most. This is the same waveform as in the previous two examples. The progressive increase of pitch in the chirp tone is vividly demonstrated by the upward sloping diagonal line. The second part of the plot, the word "Audacity" spoken aloud, again shows the greatest energy is in the center of the word.

You may want to compare this with a spectrum plot of the word 'Audacity'. That plot shows how much energy is in each frequency across the entire word, but doesn't show how the frequencies change from beginning to end of the word.

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.

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