Please kindly follow the steps below to uninstall the Apowersoft Audio Device:
1. Open finder:

2. Then, select Desktop file and use shortcut key "Command + ↑ ", keep using this shortcut key untill you see "Macintosh HD".Then, drag it to the left locations panel as the image shown below:

3. Now, enter Macintosh HD and click "Library".

4. Enter "Audio" file.

5. Enter "Plug-ins".

6. Enter "HAL" and then you will notice the file of Apowersoft audio device driver, simply delete the related file and restart Mac is alright.

And if you still cannot delete the audio device, please kindly point out that which step you are having problem with so that we can help you with it.
If you cannot find the audio device driver under HAL file, then please open Finder and select Go > Go to Folder > Enter "/Library/Extension/Apowersoft_AudioDevice.kext" and click Go, then check whether you can find the audio device driver.
Thank you for your support!