I'm wondering if the Attiny85 can be made to output PCM audio using PWM and the right timer interrupts. The Attiny85 seems capable of this, as shown at this link: http://elm-chan.org/works/sd8p/report.html
But the code is unfamiliar to me, so I'm not sure how to make use of it.
I think that someone with a better understanding of timer interrupts than me might have no trouble adapting that code for the Attiny85. Any takers? Or any tips?
Where would the audio samples come from? The ATTiny does not have much flash/eeprom/RAM to hold many samples. Serial?
If you are looking at generating specific tones for different durations, the 'tiny is good at that. At learn.adafruit.com, look under the Trinket tutorials. The Trinket Animal uses various sounds for animals (bird, cat, dog). The final code has two different functions to generate sound (one uses frequency in Hertz but uses more math). The Trinket Theramin uses that function.
If you would like to attach an eeprom external, the Trinket Audio Player would play sampled sounds, but only 65 seconds worth and it uses all the pins (SPI). I2C eeproms use less pins but do not come in large sizes.