Toolbars

• Control Toolbar (tools, play button, etc.)
• Thinklabs Toolbar (Importing and editing heart and lung sounds)
  
• Mixer Toolbar (volume controls, input device)
• Meter Toolbar (Input and Output level meters)
• Edit Toolbar (editing shortcuts)

Control Toolbar

Audio Control Buttons

	Skip to Start - moves the cursor to time 0. If you press Play at this point, your project will play from the beginning.
	Play - starts playing audio at the cursor position. If some audio is selected, only the selection is played.
	Loop - if you hold down the Shift key, the Play button changes to a Loop button, which lets you keep playing the selection over and over again.
	Record - starts recording audio at the project sample rate (the sample rate in the lower-left corner of the window). The new track will begin at the current cursor position, so click the "Skip to Start" button first if you want the track to begin at time 0.
	Pause - temporarily stops playback or recording until you press pause again.
	Stop - stops recording or playing. You must do this before making changes, edting, saving or exporting.
	Skip to End - moves the cursor to the end of the last track.

Thinklabs Toolbar

Thinklabs Special Function Buttons

	Import Audio - allows you to import sounds recordings into the current Project/Patient. If you have recorded one or more sound(s) from a patient, use Import to open the sound file. Continue to add additional files that belong to a given patient, so that the Project contains all the relevant recordings made during one exam. Each file is imported into its own separate Track. Note that Stereo recordings will import with both Left and Right. Use the Track Menu to Split Tracks, then Delete the unwanted track, and then select Mono in the Track Menu. This will convert stereo to Mono and remove a duplicate track.
	Amplify - (a Track or part of a Track must be selected to activate this function) - allows you to scale a track to be louder and softer. It is recommended that you simply Amplify to the maximum level. This can be done automatically by clicking Amplify and then OK, and the Amplify function will adjust to maximize without clipping any peaks. If you wish to control the amplification level, enter a value into the dB window. Note that a signal doubles in amplitude for every +6dB and halves for every -6dB amplitude change. Note that you can select a small segment of a waveform, such as the sounds between peaks, and amplify them significantly to enhance murmurs.
	Filter  - (a track or part of a track must be selected to activate this function) - allows you to filter a track or part of a track. There are various pre-set filters for manipulating heart sounds and lung sounds, or you can adjust the Equalizer to filter sound to your own specifications. For instance, you may find that a sharp high-pass filter (allow high, block low frequency) enables you to listen to a particular valve sounds very clearly. Merely place your cursor over the Equalization Curves, and draw the desired response to create a custom filter.
	Rate Change - (a track or part of a track must be selected to activate this function) - changes the tempo (speed) of the audio without changing the pitch. This will change the length of the selection. This is useful for expanding heart sounds so that heart sound splits, S3 or S4 and rapid events such as gallops can be slowed down and spread out.
	Display Spectrograms On/Off - allows you to view tracks with the Spectrogram below the Waaveform, or the Waveform without Spectrogram. The Spectrogram shows frequence content by showing Frequency along the vertical axis and color as the Intensity of a given frequency. For instance, if you see a bright region towards the lower part of a spectrogram, it suggests that there is a high intensity of low frequency energy at that moment in time. This is most useful for seeing murmurs or additional heart sounds such as S3 in a waveform which may not be visible on the time-domain plot of the waveform. Note that if you have a slow computer or limited memory, it is best to manipulate tracks (zoom, pan, etc.) without the Spectrogram, and the click Display to show the Spectrogram once you've zoomed in. Otherwise you may find that zooming or panning across a track is very slow.

Mixer Toolbar

The Mixer Toolbar has three controls, used to set the volume levels of your audio device and choose the input source. The leftmost slider controls the playback volume, the other slider controls the recording volume, and the control on the right lets you choose the input source (such as "Microphone", "Line In", "Audio CD", etc.). Use the Record Level Meter to set the correct level. To record from your stethoscope, connect the stethoscope to the Mic or Line Input, and select the correct Input source for the stethoscope. Then adjust the Volume Control on the stethoscope, and the Input Volume level on the slider. Generally it is best to set the stethoscope Volume Control to Maximum (10). However, check the recording for clipping of the signal which will produce distortion and annoying sound artifacts. Ideally, set the level to peak at about 50-75% of maximum. Once you have made your recordings, use Amplify on the Thinklabs Toolbar to maximize signal levels.
Changing the Speaker controls has no effect on the audio data in your project - in other words it doesn't matter what the output volume level is when you Export or Save a project - the end result is the same.

Edit Toolbar

All of the buttons on this toolbar perform actions - and with a couple of exceptions, they're all just shortcuts of existing menu items to save you time.
Holding the mouse over a tool will show a "tooltip" in case you forget which one is which.

	Cut
	Copy
	Paste
	Trim away the audio outside the selection
	Silence the selected audio
	Undo
	Redo (repeat last command).
	Zoom In
	Zoom Out
	Fit selection in window - zooms until the selection just fits inside the window.
	Fit project in window - zooms until all of the audio just fits inside the window.

Meter Toolbar

The Meter Toolbar is used for monitoring the input and output audio levels. Typically it is used to make sure that the loudest volume is as loud as possible (for maximum fidelity) without clipping or distorting it. The output (playback) meter is the green one, on the left in the picture above, and the input (recording) meter is in red, on the right.

The meters provide a visual indication of the current audio levels going in and out of audacity.

If you float the Meter Toolbar by dragging it out of the toolbar, you can resize it and even orient it vertically.

Normally the meters are only active when you are playing or recording audio. However, you can also monitor input when you're not recording - to do this, either select "Monitor Input" from the input meter's pop-up menu, or else just click on the input meter. If you have a microphone or other input source attached, you will be able to watch the level of the audio before you start recording.

Each meter shows several characteristics of the audio level at once:

• The right hand end of the meter corresponds to the point at which the audio will be clipped, and the left hand end is silence
• For stereo, the top bar shows the left channel, and the bottom bar shows the right channel.
• The brightest part of the bar shows the average audio level (related to the loudness) and the darker part of the bar shows the peak audio level.
• The peak-hold line to the right of this shows the maximum audio level achieved in the last 3 seconds.
• Finally, the clipping indicators on the far right of each meter will light up if clipping is detected (meaning that the audio was too loud and will sound distorted).
  
  
  

It is possible, especially if you have an older, slower computer, that the Meter Toolbar may interfere with Audacity's ability to record or play audio with the highest quality, because your computer is so busy redrawing the meters that it doesn't have time to process enough audio. In this is the case for you, you can disable the Meter Toolbar in the Interface tab of the Preferences dialog.