Stream audio from PC to Android 7 over USB without creating a local network
If "specialized audio transmission channels" like Bluetooth don't work I would try the generic approach over TCP/IP:


Connect your Android device to your Windows computer and enable ADB on the device (I assume adb is available on your Windows system).
Install an streaming client on Android
Install a matching streaming server on Windows 
Forward the streaming server's TCP port to the Android device via adb forward. This will allow to establish a TCP connection from Android to your computer tunneled through the ADB USB connection. For doing so no Wifi or cellular connection required or used. 
Connect the Android streaming client to the forwarded port on localhost and start audio playing