Sonic Trace draws sound as a picture. Record with your phone or open an audio file, and you get a map of frequency over time, the spectrogram, with the exact spectrum of any moment above it. A noise you could only hear becomes something you can see, point at and measure.

Why I built it
I'm an engineer in vehicle development, where much of my work has been chasing noises and vibrations (NVH). Sonic Trace is the tool I always wished I had in my pocket: pull out the phone, record the noise and see straight away what it is, at which frequency, and whether it follows the engine. It doesn't replace a calibrated measurement system. It tells you where to point one.

Find it
Spot a noise, a whine or a click and see exactly when it happens.

Follow it
Tell whether a tone stays put or sweeps up and down with speed.

Read it
Tap any line to read its frequency and level. Pinch to zoom from the whole range down to a few hertz.

Machine mode
For engines, gearboxes and fans. Machine mode tracks the reference speed: tap a line and choose which order it is, or type the RPM, and the order lines follow speed variation, even while you record.

Record, open, save
• Record live from the microphone, or open WAV, MP3 and other audio files.
• Play back with the cursor following the sound.
• Save the picture with its reading (PNG) or the audio (WAV), or copy the picture to share it.

Your audio stays on your phone
Everything is analyzed on the device. No account, no ads, no tracking. The only connection is the optional feedback form.

Levels are relative to the recording's full scale (dBFS), not calibrated sound pressure: Sonic Trace is for finding and understanding sounds, not a certified sound level meter.