Freesound Forums

No. Not if you use any instruments, samples, loops, beats (Sample Content) provided by Soundtrap [edit: and they can be sampled/extracted from your work].

6. Your use of the Service
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As a registered user, the Service provides you access to certain pre-recorded sample content including audio files, loops and beats, instruments and other sounds, sound settings, graphics, images and similar assets (“Sample Content”). The Sample Content is proprietary to Soundtrap® and/or its licensors, and is protected by applicable intellectual property laws, including but not limited to copyright. Unless otherwise is provided, you may use all Sample Content included in the Service on a royalty-free basis to create your own original Content. The Service may also provide you access from time to time to complete musical or other audio works and compositions (“Demo Projects”). These Demo Projects serve as inspiration and education only and you may not include these Demo Projects in your own Content, or reformat, mix, filter, re-synthesize or otherwise alter the Demo Projects, unless otherwise is explicitly provided in relation to the particular Demo Project. Neither the Sample Content, nor the Demo Projects may be commercially or otherwise distributed outside the Service on a stand alone basis or repackaged as audio samples or similar.

You may not distribute Sample Content to create loops or samples, and to be compliant, you would have to include this restriction in your music, which is incompatible with any license option on Freesound.

The easier it is to extract Soundtrap Sample Content from your work, the more problematic it would be to share that work under CC0 / CC BY / CC BY-NC.

Using Soundtrap without their Sample Content, or only with the CC0 sound selection or manually imported (legally compatible) audio might be OK.