The 808's sounds do not resemble real percussion, and have been described as "clicky and hypnotic", "robotic", "spacey", "toy-like" and "futuristic". "Fact" described them as a combination of "synth tones and white noise" that resembled "bursts coming from the BBC Radiophonic Workshop" more than a real drum kit. The machine is noted for its powerful bass drum sound, built from a sine oscillator, low-pass filter, and voltage-controlled amplifier. The bass drum decay control allows users to lengthen the sound, creating uniquely low frequencies that flatten slightly over time, possibly not by design. "The New Yorker" described the kick drum as the 808's defining feature.