You may be in for a tough slog with a Teensy 3.0. IIRC, the 3.0 did not have I2S support or DAC support, so it may be hard to play sounds. You might be able to emit low grade sounds by using one of the PWM pins and some capacitors and use an amplifier and speaker.
There are 2 main methods for producing sounds on Teensys:
- I2S -- which is a standard sound system that takes several fixed pins. By default I2S has stereo input and output. There are ways to extend this to quad outputs and above on some platforms;
- DAC -- this is one or two pins that you can vary the voltage on the pin. You can hook this up to an amplified speaker to produce sound. I2S tends to be better quality, but DAC pins if your board has them are cheaper.
In terms of Teensy, the sound support is:
- Teensy 3.0: No sound support as far as I am aware of.
- Teensy 3.1 and 3.2: I2S support and a single DAC pin. Note, you need to change the SPI pins if you use I2S on Teensy 3.1 and 3.2.
- Teensy 3.5 and 3.6: I2S support and a pair of DAC pins. Note, you need to change the SPI pins if you use I2S on Teensy 3.5 and 3.6.
- Teensy LC: It has a single DAC pin. It has simplified I2S support, but parts of the audio library won't run because the processor doesn't support all of the instructions needed.
- Teensy 4.0 and 4.1 has 2 separate I2S units. Unlike the 3.x, the SPI pins are not remapped. Neither the 4.0 or the 4.1 have any DACs. The 4.0/4.1 also have hardware S/PDIF support.
If you use the Teensy Audio adapter, versions A-C are for Teensy 3.1, 3.2, 3.5, and 3.6. Version D is for the Teensy 4.0 and 4.1.
The simplest approach with a Teensy 3.2 is to use the DAC and use a mono speaker with an amplifier. You can buy the speaker and amplifier separately, or you can use a combination unit.
You can get standalone I2S boards as well. Here is a mono output board that combines I2S and an amplifier for Teensy 3.2 and above. You would need to add a speaker:
Here is a unit that does stereo. It has a headphone jack that you can plug into directly, or you can plug in a stereo amplifier and two speakers;
Here is the page for the Teensy audio adapter:
Finally there are two versions of the prop shield, one with motion sensors, and one without. The prop shield includes a mono amplifier attached to the 3.2's DAC pin, so all you would need to add is a speaker. In addition, the prop shield has a built-in 8 megabyte of flash memory to hold songs. Right now it is a little inconvenient to load songs onto this flash memory, but it is hoped Teensydunio 1.54 or 1.55 will make things easier. For playing sounds, the prop shield should be mated with the 3.2.