A Letter from the Heart

Live — uses your microphone

Acoustic Freshness Tester

Hold your phone or laptop mic near the fruit and tap it with a knuckle or spoon. This listens continuously, detects the tap by its amplitude spike, and runs a real FFT on the sound to find the resonant frequency — no simulated data here.

Testing

Mic off

Trigger sensitivity

5 — medium

Average next 3 taps

Live microphone input

trigger threshold

Live frequency spectrum

magnitude last detected peak

Press "Start listening" and allow microphone access

-- Hz

 

How to get a clean reading: find a quiet room, hold the mic 3–6 cm from the fruit, and tap firmly once with a knuckle or the back of a spoon. If it doesn't trigger, raise the sensitivity slider or use manual capture right after tapping.

Honest limits: the fixed frequency thresholds here were set for demonstration, not calibrated against real produce — fruit size and mass shift resonance independently of ripeness, so the same threshold won't generalize across very different sized fruit. Phone microphones also vary in how they pick up low frequencies. Treat readings as illustrative, not a substitute for checking the fruit yourself.