I am a sixty-year old guy who wants to prevent his brain from getting too tired and lazy. I have had done some programming in different languages (Clipper, VB, PHP, Visual C, not C++) roughly 20 years ago and would like to start a small project with an Arduino Uno Rev. 3 to record some machine noise with a body sound sensor, and to play it back via connected speaker. Sounds to me pretty easy (in the beginning). Nevertheless I have recognized that I have some minor difficulties to start with this and would be pleased for any kind of assistance (samples, sniplets, advice). Mayn thanks in advance from Hamburg, Germany!
Sounds to me pretty easy
Sorry it is not.
The Arduino has very little memory and no D/A converter. So you have to built those on. You require an SD card and a D/A. The simplest way to get these is an Adafruit wave shield. You would also need a microphone and amplifier, to feed the signal into the A/D.
You should be able to do your project with this extra hardware. It is possible to kludge an A/D but in my opinion it is not worth it.
This link covers what you need to do:-