This audio adaptor lets you easily add high quality 16 bit, 44.1 kHz sample rate (CD quality) audio to your projects with Teensy 3.0, 3.1, 3.2, 3.5 or 3.6. It supports stereo headphone and stereo line-level output, and also stereo line-level input or mono microphone input.
The Teensy Audio Library lets you use the input and output simultaneously together with a toolkit of audio processing objects, to easily create all types of sophisticated audio applications. You can play multiple sound files, create synthesized waveforms, apply effects, mix multiple streams and output high quality audio to the headphones or line out pins.
Teensy 3.x have the Cortex-M4 DSP instructions which provide plenty of computational power for real-time FFT (spectrum analysis), opening up the possibility of creating advanced sound-reactive projects.