Audio Microscope — Pitch-Preserving 500x Slow-Down

Regular slow-motion lowers the pitch — everything sounds deep and muddy. Audio Microscope keeps the original pitch. For moderate slowdown it uses a transient-preserving stretcher (Signalsmith) so attacks stay crisp; for extreme slowdown it switches to Paulstretch, which turns the moment into a smooth, stable spectral freeze instead of a metallic stutter.

No single algorithm sounds right across the whole 2x–500x range. Auto picks the best engine for the factor. Detail keeps the recognizable, transient-preserving engine up to higher factors; Texture switches to the smooth Paulstretch freeze sooner. Pitch is preserved either way.

Short, sharp sounds reveal the most: a finger snap, a clap, birdsong, glass breaking, raindrops, a mosquito, the click of a keyboard. Even 5x–10x reveals surprising structure; 100x–500x turns a fraction of a second into a slowly evolving texture.

Processing runs in your browser, so the slowed output is capped at a couple of minutes. Because a tiny region becomes very long at high factors (0.5 s at 500x is over 4 minutes), select a short region for extreme magnification — the tool tells you if it trims your selection.

Move the cursor over the spectrogram to read the exact time in the original recording, the frequency in Hz, the nearest musical note with cents, and the level in decibels at that point. Switch between a logarithmic and linear frequency scale and adjust the dynamic range to reveal faint detail.