The PT2258 6-Channel Electronic Volume Controller is unfortunately not a mixer, but "just" a 6 channel attenuator, otherwise i would have bought a handfull by now :-)
The idea is that I have a store of several small 16bit wave files (about 3 secs each), probably on a SD card or some other permanent storage memory.
When the appliance starts I need to load them to some fast memory device and then commanded by the Arduino, command the sound wave sound that plays on each channel or even better, some chip that I just send the wave to play and it mixes to the final output, together with other already playing waves.
I know I cannot use the Arduino memory for that. The Arduino will act as the main controller between the audio part and the sensor part, reading the sensors and commanding the audio.
I’ve seen some projects with memory but I’ll worry about that later when I have the solution for the audio mixer because that seems to be the most difficult past, at least Arduino related as I didn’t manage to find anything on that.