Sound layers add sound effects and music to a page to punctuate actions and add atmosphere.
The Motion Book Tool offers two different methods to add a sound layer to a page. A bounding box appears on the page for whichever method you use. You can ignore the bounding box—it’s just there to show that the sound layer is selected.
To Add a New Sound Layer to a Page Using the New Layer Button
1. Click + on the Add New Layer button at the top of the page’s layer stack.
A dialog box appears asking what kind of layer you’d like to create.
2. Click Sound then click Done or double-click Sound.
The dialog box closes and a new sound layer box appears at the top of the layer stack. The sound layer box is open and presents image layer controls. The content box at the top of the layer box is empty because the layer doesn’t yet contain a sound.
3. Drag a sound asset from the asset bar and drop it on the content box.
The sound file name appears in the content box.
4. Click in the layer box heading to select the name “sound” and replace it with a name that describes the content.
To Add a New Sound Layer to a Page by Dropping it On the New Layer Button
l Drag a sound asset from the asset bar and drop it on the + of the Add new layer button at the top of the layer stack.
A new image layer box appears at the top of the layer stack with the name of the sound file in the content box.
A sound layer doesn’t play on a page until after you’ve added a Fade In effect to it (described in “Fading Sound Layers In and Out” on page 167). To hear the contents of a sound layer before you add effects, open an asset tab for the layer’s sound asset.
To Play a Sound Layer’s Sound Asset
1. Click the content box at the top of the sound layer controls.
The Motion Book Tool opens an asset tab containing the sound asset. The workspace of the tab contains playback controls.
Figure 1: Sound asset playback controls.
2. Click the Play button once to start playback; again to pause it during playback.
The playback time box displays the number of seconds already played.
You can dismiss the sound asset tab when you’re done listening.
A sound layer has few of the common controls shared by graphic layers, and instead offers controls for sound playback on the page.
Figure 2: Sound layer controls set sound playback.
To Set Sound Volume at Playback
l In the sound layer controls, drag the Volume slider right for higher volume, left for lower volume.
l In the sound layer controls, enter a Volume value from 0 (silent) to100 (full volume).
A loop is a single play-through of a sound file. A sound layer is set by default to play a sound asset once and then stop. You can set the sound to loop multiple times once playback begins.
To Set Playback Looping
l Set the Loop value to a value greater than 1.
When the sound plays on the page, it loops the specified number of times unless playback stops for some other reason (an effect stops it or the reader moves on to another page, for example).
When you add a sound layer to a page, it doesn’t play until you add an effect to it that specifies the time when the sound layer starts playback. Once a sound layer begins playback, it continues for the specified number of loops and then stops unless another event stops the sound before it’s finished playing (a fade out effect, for example).
The amount of time a sound plays often varies, especially if the sound is a long track or is set to loop many times. Because a page is paced by a reader using tap points, it’s unknown how long a reader will linger between tap points with a sound playing. If you want a sound to continue for the duration even for a slow reader, set the loop value to a very high value such as 999.