Morse code is basically dashes and dots. Each character is encoded using a mix of them. Human can learn Morse code during some practice. If you don’t want to learn it but still need to decode some messages you can build a simple Morse code interpreter which listens to beep signals and translates messages in to readable text.
This system is based on Atmega8 microcontroller which reads sound signals using microphone and operational amplifier. Then microcontroller reads sound signals using ADC and determines weather particular signal were dash or dot. It can translate 32 characters including aA- zZ and 0-9. Messages are displayed on standard 2×16 LCD.