Introduction

The Audio Annotation Tool lets you add notes to time segments on an audio timeline. You can listen to the audio clip, mark a time segment, play back the segment, or attach your written notes to the segment.

The tool is used to play and annotate MP3 files. There are four areas of the user interface:

1.	Use the Chooser to select and open annotation documents; to change the title of an annotation document; or to save a copy of an annotation document.
2.	Use the Playback Control to play the audio clip. This panel provides play, pause, fast forward, restart, and volume controls, as well as a slider for controlling the play time.
3.	Use the Note Editor to edit annotation text.
4.	The Timeline displays the audio clip's time scale, the current playback time, and tracks with annotation segment markers. The controls let you add or remove annotations and undo or redo your changes.

Opening an Audio Annotation Document

Use the Chooser to select an audio annotation document to edit with the tool. An annotation document links to but doesn't contain the audio clip you are annotating. To open an annotation document:

1.	Click on the "Open" button (). A dialog box will appear showing the workspaces and folders available to you. Your personal workspace tab will be highlighted.
2.	Select a workspace tab by clicking on it.
3.	Within a workspace, red triangles () mark nested folders. Clicking on a triangle reveals additional folders and individual resource items. Audio annotation documents appear in black. Scroll down and click on the name of an annotation document, then click "Open" to open it in the tool.

Playing Audio

In the Playback Control area, click the play control to begin playing the clip. The progress slider indicates the playback time. You can drag the slider indicator right or left to change the current playback time.

Use the volume control () to raise or lower the volume of the audio.

Use beginning and end controls () to return to the beginning or jump to the end of the clip.

Navigating The Audio Timeline

Use the scrollbar under the timeline to slide it left or right.

You can change the current playback time by clicking on the ruler. The current play time and marker will jump to the point where you click the mouse.

The zoom buttons change the timeline's time scale. You can zoom out to see more of the timeline (even view annotations over the entire audio clip) or zoom in on a particular section.

Controls to zoom the time scale are at the bottom of the Timeline, below the segment marker tracks:

The "zoom in" control () will display shorter and shorter portions of the timeline with greater detail.

The "zoom out" control () will display longer and longer portions of the timeline, with less detail. You will not be able to zoom beyond the duration of the entire clip.

Adding a Note To The Timeline

The Audio Annotation tool lets you add notes to time segments on the timeline. Segments with notes appear as colored markers that on the timeline's tracks. When a segment is selected its text will appear and may be edited in the note area.

To create a note with the Audio Annotation Tool:

1.	Find the beginning of the audio segment you wish to annotate. Change the current playback time by clicking on the ruler at the top of the timeline or by pressing the Play button to play the audio clip.
2.	Click the New Note button () to create a segment marker on the timeline. A marker will start at the current playback time. Initially the segment is set to a length of six seconds.
3.	Continue listening to find the end of the audio you are interested in marking. Click the "pause" button () in the Playback Control. This will stop the red progress needle in the timeline.
4.	Click and select the new segment marker. Endpoint handles will appear at either end of the segment.
5.	Adjust the segment start time by dragging the left handle and adjusting the end time by dragging the right handle. You can also slide the segment by clicking and dragging over the middle of the marker.
6.	Change the marker's track by clicking the middle of the marker and dragging it up or down.
7.	Click on the "Play Segment" () button to play back your new annotation. You can drag the endpoint handles to adjust the beginning and end points of the segment.
8.	With the endpoint handles still visible, go to the Note area and click the "Edit" button () to enter text that will be associated with the annotation segment. Formatting controls for making text bold, italic, indented, and the like are available to style the text.
9.	You can choose a color in the note panel's color picker (). Selecting a color will change the color of the marker on the timeline.
10.	When you are finished editing the note click the "Save" button to save your changes.

Removing Notes From The Timeline

To remove a note from the timeline, select the marker in the timeline control, then click the "Remove" button.

Undoing and Redoing Your Changes

The Audio Annotation Tool keeps track of every change you have made starting with the time you last opened the tool. Use the "Undo" button on the timeline's left panel to undo your last change. You can press the button more than once to undo earlier changes. Press the "Redo" button one or more times to redo changes you have undone.

Changing the Title of the Document

To edit the title of the current document, click the "Edit Title" button (). Click inside the title box and type in a new title. When you are finished, press the save button or cancel to restore the title.

Saving a Copy of the Annotation Document

The "Save As" button allows you to save a copy of the annotation document. When the "Save As" button is clicked, you can choose a workspace and folder in which to save the document. If you want to use the same folder to store the revised annotation document, you will need to give the clip a new file name. This will prevent the overwriting of any earlier annotation documents that may be in the folder.

Preparing Audio for Annotation

In order to add media to Project Pad you will need to encode it in a form that can be used by Project Pad tools. The audio annotation tool expects audio files encoded in MP3 format. We recommend bit rates from 16 to 32 kbps. The open source LAME utility program (http://lame.sourceforge.net/) can be used to encode files for annotation.

Once you have prepared the audio files in the proper format, you need to place them in a directory that is visible to the Project Pad system. If you are running with the default configuration in Project Pad, then you already have a folder /sakai-ppad/media that is visible to the system. Just drop your files into this folder.

Use the "Import" button () to create a new annotation document for your audio clip. Click "Import" and use the dialog to select the audio file. Press "Open" to create a new annotation document for that clip. The "Save As" dialog will open to allow you to save the new document.