Sound Explorer Help
Getting started
- Open a recording — drag and drop a WAV file onto the window, or click Open Files.
- Navigate — scroll to zoom, click to seek, press Space to play/pause.
- Change speed — use the Play as selector to slow down or speed up. Playing a 384 kHz bat call at 0.0625× makes it audible.
- Select & export — shift-click to select a region, then click Export WAV.
Live audio input
- Click Live to capture audio from your microphone or sound card.
- The spectrogram updates in real time. Use the View selector to change the visible time window (2–30 seconds).
- Click Rec to record a segment.
- Click Stop Live — the recording loads automatically for playback and export.
Your browser will ask for microphone permission the first time. On macOS, you may also need to allow access in System Settings → Privacy & Security → Microphone.
Keyboard shortcuts
| Key | Action |
|---|---|
| Space | Play / Pause |
| ← / → | Seek −1s / +1s |
| Shift+← / → | Seek −10s / +10s |
| ↑ / ↓ | Increase / decrease spectrogram gain |
| Scroll wheel | Zoom in / out |
| + / - | Zoom in / out |
| F | Fit entire file in view |
| S | Zoom to selection |
| T | Trim view to selection |
| U | Untrim (restore full view) |
| L | Toggle loop |
| G | Focus Go-to time input |
| Home / End | Jump to start / end |
| Esc | Clear selection |
Spectrogram controls
The bottom panel contains spectrogram display settings:
- Brightness & Contrast — adjust the visual mapping of amplitude to color.
- Range (dB) — dynamic range of the colormap (e.g. 90 dB shows a wider range of amplitudes).
- FFT size — larger values give better frequency resolution but less time precision. 2048 is a good default. Use 8192 or higher for narrowband analysis.
- Window function — Hann (default), Blackman-Harris (less spectral leakage), Hamming, Flat-top.
- Colormap — viridis, magma, inferno, grayscale, green, hot.
- Frequency range — set min/max Hz, or use presets (Full, Birds, Voice, Low, Mid). Toggle logarithmic scale.
- Channel mode — mono downmix, left only, right only, or split L|R display for stereo files.
Selection and export
- Select — shift-click to set selection start, shift-click again to set the end. Or click the Sel button and drag.
- Loop — press L to loop the selected region.
- Export WAV — exports the selection as a WAV file. If you have a non-native playback speed selected, a second export button appears to export with the speed change applied.
- Trim — press T to crop the view to the selection. Press U to restore.
Exported files preserve BWF timecode metadata when present in the original. The audio is exported at original quality — no transcoding.
Supported formats
| Format | Bit depth | Sample rates |
|---|---|---|
| PCM WAV | 16-bit, 24-bit, 32-bit | Any (tested up to 384 kHz) |
| IEEE Float WAV | 32-bit | Any |
| WAVE_FORMAT_EXTENSIBLE | All above | Any |
| BWF (Broadcast Wave) | All above | Any |
Only WAV files are supported. To convert other formats, use FFmpeg:
ffmpeg -i input.mp3 output.wav
Annotations
Label time regions with notes. Annotations appear as colored overlays on the spectrogram.
- Select a region, then click Notes in the toolbar to open the annotations panel.
- Add a label and optional description.
- Export annotations as JSON for later import or analysis.
Tips
- All processing happens locally in your browser — your files never leave your device.
- After the first visit, Sound Explorer works offline as an installable PWA.
- Chrome is recommended for best performance with large files and live audio input.
- For multi-file sessions and iXML metadata support, use the desktop app.