To compare 2 records (wave files) select both files in the explorer/navigator and select "impulse->Compare with each other" in the context menu.
impulse will prompt you for comparison setting and opens a new viewer finally.
Options:

• Scope tree: to limit diff to the containing signals.
• Signal filter: to apply comparison to matching signals only.
• Ignore if 2nd input is ...: Select if the 2nd record may contain longer or shorter content (just compare the common domain delta).
• Hide identical content: Select if impulse shall hide signals without diff.
• Prepare delta for ...: Select if impulse shall generate delta signals for numerical signals (float, integer).
• Append both original inputs : Select if impulse shall add the original signal as children of the generated diff or delta signals.

You may press the "Reload Input" button to change the options.

In the signal area of the viewer you will find the following annotations:

• Scope different: There are changes between 1st and 2nd record within this scope or a sub-scope.
• Signal different: This signal differs between 1st and 2nd record.
• Signal added: This is a new signal in 2nd record that is not available in the 1st record.
• Signal removed: A signal in the 1st record is not available in the 2nd record.

You may use the Diff flag in the search field to filter all changes.

The available signals in the viewer are either:

• The original signal if signal1 and signal2 are identical
• A new diff signal
  • Contains only signal content that is equal between the 2 sources.
  • Shows a yellow thick line in all areas with different content.
• or a delta signal in case of a numerical signal input,
• and the original input signal named 1_name and 2_name as child signals (if enabled).

If you choose a new view, its preferable to choose a hierarchical or empty view.

Instead of comparing complete records, you may want to compare signals inside of one record.
To do so, open the plot dialogue (you may take the existing plot of one of the signals or create a new plot), select "Diff" or "Delta" in the production field, check the diff/delta parameters (that will appear after selection) and make sure that the 2 signals are added as sources (if you started with the existing plot, you just have to add the 2nd signal).
The output of the "Diff" production is:

• The original signal if signal1 and signal2 are identical
• A new diff signal
  • Contains only signal content that is equal between the 2 sources.
  • Shows a yellow thick line in all areas with different content.

The output of the "Delta" production is the numerical delta of 2 numerical input signals (integer, float).