I'm working through a Linux textbook, and it's telling me about devices.  It says that if I send the appropriate output to /dev/dsp, then it will play a sound.  The example is cat file.wav > /dev/dsp, where file.wav is just any .wav file.When I do this I get permission denied.  If I run this with sudo I still get permission denied.  If I su first, no sound plays.  Why do I get permission denied with sudo?  Why does no sound play even with su?
Why won't Linux let me play with /dev/dsp?
linux mint;devices