User:PeterSampson/Sand-Box

Audacity Tour Guide

This guide provides a quick tour of selected features of Audacity. This page doesn’t tell you how to use features, it would be much too long if it did. Rather it tells you about some of the features that exist in Audacity and will help you learn a little about those.

There are many links on this page (highlighted in blue), click on those to go to the more detailed pages in the Manual.

Contents

1. Record, Play and Edit - Audacity basics
2. Saving your work
3. Editing tools
4. Things you might not know Audacity could do

RECORD, PLAY, EDIT - these are the basics of Audacity

RECORD: - Open Audacity. Click the Record button in the TRANSPORT TOOLBAR near the top left. Audacity should start drawing a waveform showing the recording in progress. Without a microphone or other input device the recording will be a flat line indicating silence. With a working microphone or input device selected the line will squiggle up and down depending on how loud the sounds are. If recording 'just doesn’t work' there is a detailed guide in the FAQs that can help you find out why.

MONITORING: To see on a visual scale how loud your audio recording will be, click on the RECORDING METER. Monitoring does not stay on after recording or playback, so you may find yourself clicking monitoring back on after making a recording.

PLAY: - Get some sound to play in Audacity first, possibly by recording (or in the menus click GENERATE then CHIRP, and then click the OK button). A track with a waveform should appear if you do that. Now click near the start of the waveform and a thin vertical line will be positioned on it. That is where playing will start from. Now click the Play button , also in the Transport Toolbar. Playing should start when you do, you should hear something on the speakers or headphones. To stop playing before the end, click the Stop button , that’s the button just to the right of Play. To quickly select and play audio in one go, use the QUICK-PLAY feature which is accessed from the TIMELINE, the horizontal ruler above the display of tracks.

EDIT:- You can edit audio once you select it. You select audio by click and dragging the cursor left to right across the piece of audio you want to change. You can apply EFFECTS from the Effect menu, and you can cut or paste the selected audio using the buttons showing scissors or clip board. You could instead of buttons use keyboard shortcuts, Ctrl + X or Ctrl + V for cut and paste (Command + X or Command + Y on a Mac). You still need to select the audio first.

Saving your work

SAVE: - Audacity makes a distinction between saving audio in AUDACITY PROJECT FORMAT and exporting audio in formats like WAV and MP3. Audacity project format is made up of multiple files. There are many ‘.au’ files in a folder and one ‘.aup’ file that says what order the files are in. Don’t edit these by hand or separate the .aup file from its .au files. You’ll lose work if you do.

EXPORT Use Export if you want to create a file in an audio format for playing outside of Audacity.

Editing tools

LOUDNESS: The AMPLIFY audio effect makes audio louder or quieter. Two other effects that modify loudness are FADE IN and FADE OUT. These are often used at the beginning and end of audio.

ENVELOPES provide a more flexible way to control loudness. You will need to select the ENVELOPE TOOL or MULTI-TOOL to use envelopes. With envelopes you can graphically control when audio gets louder and quieter.

NOISE REDUCTION: Audacity can remove some kinds of noise from a recording. Noise Reduction is an ‘audio effect’ one of the fiddlier audio effects to use. The effect works best with fairly constant noise like background hiss. You first select audio that is just the noise and create a ‘noise profile’. Once Audacity knows the noise profile, it can reduce the loudness of noise of that kind in audio you select.

'TRUNCATE SILENCE: a convenient effect to apply to recordings of interviews and speeches that removes long silences. You can tell it what to count as a long silence, the loudness level and duration, and how much of each long silence to remove.

DRAW TOOL: If you ZOOM in enough on Audacity audio you can edit individual samples of audio. Typically there are 44100 values for every second of audio. This shows something of how audio is held in the computer. Very occasionally there may be a click in audio which is better removed with this Draw Tool than with a CLICK REMOVAL or the REPAIR audio effect. The repair audio effect is best used when zoomed in a lot as it only works with short pieces of audio.

VARYING AUDIO SPEED You can modify the audio itself to speed it up or slow it down by applying an effect.

Use CHANGE SPEED effect to make audio faster or slower and higher or lower pitched.

Use CHANGE TEMPO effect if you want the pitch to stay the same even when audio is faster or slower. Change Tempo does not always work so well with large changes in speed and the end result may sound a bit strange.

TIME TRACK is another way, a more flexible way, to change the audio speed. It is like the Change Speed effect in some ways, but instead of a constant speed up or slow down, you must say how the speed should vary moment by moment. Save a copy of your work, for example by exporting it to WAV format before using the Time Track. It is one of the less widely used parts of Audacity.

LABELS: Use a Label Track to mark or annotate audio. In conjunction with Sync-Lock you can keep the labels and audio in step.

UNDO AND REDO: These are most useful when working with effects. After you have applied an effect you might change your mind. The Undo button or menu item Edit > Undo will let you undo the change. The HISTORY menu item lets you look further back in time and undo more changes in one step.

Things you might not know Audacity could do

LAME: Do you want to convert a recording to compressed MP3 format? Audacity can, but it needs an add-on to do so. The add-on is a library called ‘LAME’. A free copy of LAME that is compatible with Audacity is available from Buanzo, an IT security consultant in Argentina. It’s a download fromlame.buanzo.org. Full details of what to do with it in the Audacity manual.

PLAY-AT-SPEED Audacity has a TRANSCRIPTION TOOLBAR with a small button with green arrow pointing right. It’s very like the larger button with green arrow for ‘Play’. You set the speed, faster or slower, using the slider that is to the right of the button. You need to stop and restart playback for the new speed to happen.

SCRUBBING AND SEEKING is the action of moving the mouse pointer right or left so as to adjust the position, speed or direction of playback, forwards or backwards, listening to the audio at the same time - a convenient way to quickly navigate the waveform to find a particular event of interest. You can also use the mouse wheel to change playback speed and have the speed change as the audio plays, so this is another wat to change playback speed.

CHAINS: Ever want to do the same thing to a large number of audio files, for example remove noise from them and convert to MP3? Chains is the feature for this. It was originally written for converting large numbers of sermons. You give it a list of files to work through and tell it what sequence of things to do. Programmers may want instead to use a more flexible version of chains. There is an experimental feature called ‘scripting’ that needs a free experimental add-on called mod-script-pipe and experience in programming.

EFFECTS PLUG-INS: You can add to the effects available in Audacity using plug-ins. Some of these have very nice looking GUIs and provide more options than the effects that ship with Audacity do. There are several types of plug-in. The NYQUIST type of plug-in, for example, is used to prototype new audio effects. Separating voice from other audio, e.g a song from background music, or completely removing pops clicks and ‘breath sounds’ from a voice recording, are hard to do. Some optional Nyquist effects aim to do such tasks. They have varying degrees of success. In the right circumstances these effects can be useful.

MULTI-CLIP: Many people have a single piece of audio on each audio track. However, you can have multiple piece of non-overlapping audio on the same track. These are called clips. Clips can be created with SPLIT and joined back together by clicking on the BOUNDARY BETWEEN CLIPS. If you click the TIME SHIFT TOOL you can drag clips around to different positions on the track, or drag onto different tracks.

SYNC-LOCK: When you have a mix, i.e. several tracks above each other which play together, and when everything is nicely lined up, edits in one track, e.g. cutting a piece of audio, can cause the audio no longer to be lined up, and the tracks no longer to play in sync. To keep the tracks aligned despite cut and pasting audio, use Sync-Lock.

LOOP PLAY: Hold shift down before clicking play, and you will get Loop Play. Shift also changes whether record adds to the end of the existing audio or adds audio below, for a mix.

SPECTRAL SELECTION: This is a special feature within SPECTROGRAMS, which are a way to view the frequency content of audio. Spectral Selection allows you to work on and edit just selected frequencies. This is particularly useful for voice recordings.

SNAP-TO: When making selections it sometimes is helpful for the selection boundaries to be automatically moved to the nearest second (or some other unit of time measurement). If you ‘snap-to’ seconds your selections will always be whole numbers of seconds - you can’t select half a second of sound for example.

SHORTCUTS: Many buttons and menu commands have pre-defined keyboard shortcuts assigned. You can modify these or add your own with Keyboard Preferences from the Edit > Prefences menu.