> Tyle tylko, że mi nigdy nie chodziło o odtwarzanie na tym muzyki, ale
> raczej jakichś nagranych wcześniej komunikatów głosowych. W tym
> przypadku wystarczająca będzie jakość zbliżona do tej oferowanej przez
> telefonię analogową.

AVR335: Digital Sound Recorder
with AVR and DataFlash

Features
oDigital Voice Recorder
o8-bit Sound Recording
o8 kHz Sampling Rate
oSound Frequency up to 4000 Hz
oMaximum Recording Time 4 1/4 Minutes
oVery Small Board Size
oLess than 700 Bytes of Code

Introduction
This application note describes how to record, store and play back sound
using any
AVR microcontroller with A/D converter, the AT45DB161B DataFlash memory and
a
few extra components.
This application note shows in detail the usage of the A/D Converter for
sound record-
ing, the Serial Peripheral Interface - SPI - for accessing the external
DataFlash
memory and the Pulse Width Modulation - PWM - for playback. Typical
applications
that would require one or more of these blocks are temperature loggers,
telephone
answering machines, or digital voice recorders.
[...]

http://www.atmel.com/Images/doc1456.pdf