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IntroductionSignal Manipulation > Spectrum Manipulation and Treatments > Selection Tools
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Selection Tools

AS offers a panel of selection tools that are used for the selection of differents types or time frequency regions or spectral components in a sonogram.

Tools Palette


The selection tools are accessed with a click on the second item of the palette located at the top of the AS window.

Tool Types

Five selection tools are available :

  • Rectangle : draw a rectangle selection with a click and drag

  • Free surface : draw any type of surface with a click and drag

  • Magic wand : select components of similar amplitude

  • Zoom : zoom in a selection

  • Lasso : select several regions


The rectangular selection tool is selected by default. To select a tool, click on it an select a menu item.

Each tool can be selected pressing a specific key.

The selected tool will then be displayed in the palette.

Automatic Selection Tools Conversion

Clicking with any of the selection tools in the global waveform window converts it into the player on the fly, represented by a loudspeaker.

Selection tools are automatically converted into a standard pointer when browsing the processing sequencer.

Playing a Sound on the Fly


Rectangle and Free Surface

The rectangle and free surface allow to select :

  • a time/frequency region in the sonogram window

  • a temporal segment in the waveform window.

To draw a figure, click and drag the pointer on the sonogram. The free surface will be automatically completed when releasing the pointer.

Magic Wand

The magic wand allows to select time/frequency regions of equal amplitude. Click in the sonogram to select a region.

The magic wand settings define the tolerance level in dB for the continuity of the spectral components selection. Select the Magic Wand Settings menu item with a click in the palette and enter a value in dB in the dialogue window. A high tolerance level in dB means what it means : a region accepts components with an important difference in level, so that it incorporates more components.


To preserve the magic wand selection when changing the tolerance level, uncheck the Update Selection option in the Inspector window. Otherwise, your selection will disappear.


The zoom tool allows to zoom in a desired time/frequency region, in the waveform, sonagram or instantaneous spectrum. The red selection rectangle of the global waveform window will match the selection.

  • Click and drag a region to zoom in.

  • Alt click to zoom out.

To reset the representation to the global scale, double click in the sonagram or on one of the time or frequency scales.


The lasso allows the selection of several time/frequency region in the sonogram.

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