Ocean Sound Synthesizer

This fun project synthesizes the sound of the ocean surf. I designed and built this project in 1990.

The circuit consists of two 31-bit linear feedback shift registers that clock at 150KHz and 150Hz, respectively. The first LFSR generates white noise and low-pass filtered white noise. The second LFSR is low-pass filtered and used to amplitude modulate both noise components from the first LFSR. The signal is amplified and drives a small speaker.

The use of digital techniques means that the rise-and-fall sound generated by the circuit is not truly random, but repeats with a period of about half a year! Also, the circuit generates the same sequence of sounds every time it is turned on.