diff --git a/README.md b/README.md
index 1346a9f..4fdc399 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,26 @@
 	- the board will go into bootloader mode and appear as USB thumb drive
 6. Copy the `soundcube-firmware.ino.uf2` file to the thumb drive and wait for the board to restart
 
-## config.txt
+
+## SD Card contents
+
+
+´´´
+config.txt
+click.wav
+sound/
+  ├─ 1.wav
+  ├─ 2.wav
+  ├─ 3.wav
+  ├─ 4.wav
+  ├─ 5.wav
+  ├─ 6.wav
+  ├─ 7.wav
+  ├─ 8.wav
+
+´´´
+
+### config.txt
 
 Json formatted config file. For now only edge led color working.
 
@@ -25,11 +44,38 @@ Json formatted config file. For now only edge led color working.
 }
 ```
 
-## click.wav (not played correctly)
+### click.wav
 
 Put a file called `click.wav` (not longer than a few seconds) in the root of the SD card and it will play when you press a button.
 
 
+### Sounds
+
+Put all sounds into the ´/sound´ subfolder. Name them ´1.wav, 2.wav, 3.wav...´
+
+
+## Wave File Format
+
+Export all sounds except ´click.wav´ as **48000Hz (48kHz) 16bit Stereo**.
+
+### Audacity
+
+You can use Audacity to export all soundfiles to WAV format.
+
+1. Load file into Audacity
+2. Select Track
+3. File -> Export Audio
+
+#### Format options in Audacity
+
+- WAV(Microsoft)
+- Chanels: Stereo
+- Samplerate: 48000Hz
+- Encoding: Signed 16-bit PCM
+
+
+----
+
 ## Code something yourself
 
 1. Download [Arduino IDE](https://www.arduino.cc/en/software/)