You can edit Waveform Regions on the timeline.

Editing in the timeline supports the following operations.
Please refer to the link for more information.

If you want to make numerical adjustments, please refer to the link below:

Edit by numerical specification

Timeline tool

The timeline tool can perform operations according to the functions on the timeline.
Click the icon on the timeline toolbar to switch tools.

Name	Icon	Keyboard shortcut	Operation
Selection tool		1	Region Selection, Move, Trimming, Fade Settings
Split tool		2	Multiple selection of regions, split

Region editing features and notes

Editing in the timeline is nondestructive, and trimming or fading do not affect the waveform file registered in the project's materials.

Note on file size

Generally, when creating an ACB (or AWB), only one material will be packed into an ACB (or AWB), even though multiple regions refer to the same material.
However, the edited regions are encoded as separate waveforms according to the parameter contents and packed into ACB (or AWB).
For example, in the case of applying fades having different set values to fade pattern 1, pattern 2, pattern 3 and three regions that refer to waveform A,
Waveform encoding is performed for each region, and they are all packed into ACB (or AWB).

However, not all the materials edited in the region will be registered as individual materials.
When all of the following conditions are met, it is still regarded as the same material, and only one is packed in ACB (or AWB).

Same trimming range
Fade in time, curve strength, curve type are all the same
Fade out time, curve strength, curve type are all the same

Note: For example, in the case of rhythm games etc., if you use the BGM of one song while trimming only the rest for the song selection screen, the total size will be "original data + song selection part".
In addition, when multiple serifs are stored in one waveform file in a dialog, etc., the amount of deleted data can be reduced by deleting silent parts by dividing or trimming.