SpectraHold

The spectrogram with memory.

SpectraHold turns microphone input into a 3D spectrogram. Watch frequencies in real time, freeze the view, and explore up to 120 seconds of visual history to inspect a detail you just heard.

FREEZE AND EXPLORE Tap the graph to inspect a frequency. Zoom and browse the history, then return to live analysis whenever you want.

ADJUST THE VIEW Choose a visible window from 1 to 20 seconds, color palettes, and automatic or manual visual gain from −40 to +40 dB. Visual gain changes the graph without changing microphone gain.

FEATURES • Real-time 3D spectrogram from 20 Hz to 20 kHz. • Adjustable history from 20 to 120 seconds. • Frequency inspection, zoom, and history navigation. • Up to two estimated peaks per region: bass, midrange, and treble. Detection does not confirm resonance. • Background capture and capture with the screen locked, while permitted by the system. • Compatible with iPhone and iPad.

Audio is processed on your device. History stays in memory; no audio file is saved or uploaded. Closing the app or a system interruption may stop capture.

TRIAL AND PURCHASE Download for free. Activate a free 7-day trial to access all features. After the trial, analysis stops until you purchase full access. The unlock is a one-time purchase, with no subscription or automatic charge. The local price is shown before you confirm the purchase. You can restore purchases.

SpectraHold is a visual analysis tool. It does not apply equalization, automatically eliminate feedback, or replace a calibrated sound pressure level meter. Estimates depend on the microphone, device, and recording conditions.

Discovery signals