Microcontrollers typically don’t have a lot of on-board memory, so the idea of playing audio samples is generally out of reach without somehow solving the storage issue or delving into synthesised sound.
But it is possible to play (very) short samples. In this example I’m playing an 8kHz, 8-bit sample stored in flash memory, using the PCM library to modulate a PWM output accordingly.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
And here’s an Uno pretending to be a phone, just to prove the point…