Getting Started with iNatSpectro

Table of contents

  1. What is iNatSpectro?
  2. Basic Usage
    1. Automatic Spectrogram Generation
    2. Understanding the Spectrogram Display
  3. Interactive Controls
    1. Zoom and Pan Navigation
    2. Audio Playback Synchronization
  4. Settings Panel
    1. Live Parameter Adjustment
    2. Species-Specific Profiles
  5. Advanced Features
    1. High-Resolution Analysis
    2. Performance Optimization
  6. Tips for Best Results
    1. Getting Started
    2. Troubleshooting Common Issues
    3. Best Practices
  7. Next Steps
  8. Getting Help

What is iNatSpectro?

iNatSpectro is a professional-grade browser extension that automatically generates high-resolution bioacoustic spectrograms for audio observations on iNaturalist. It transforms audio recordings into visual frequency-time representations, making it easier to analyze and identify animal sounds.

Basic Usage

Once installed, iNatSpectro works automatically on iNaturalist observation pages with audio content.

Automatic Spectrogram Generation

  1. Navigate to an iNaturalist observation that contains audio
  2. The extension automatically detects the audio and begins processing
  3. For audio files ≤1 minute: The spectrogram appears immediately below the audio player
  4. For longer files: Click “Render Full Spectrogram” when prompted to generate the visualization

Understanding the Spectrogram Display

The spectrogram shows three dimensions of sound information:

  • X-axis (Horizontal): Time progression in seconds
  • Y-axis (Vertical): Frequency in Hz (can be logarithmic, linear, or mel scale)
  • Color intensity: Sound amplitude using the Viridis colormap
    • Purple/Dark: Quiet or absent sounds
    • Green/Blue: Moderate intensity
    • Yellow/Bright: Loud sounds

Interactive Controls

Zoom and Pan Navigation

Zoom Controls:

  • Zoom Slider: Adjust magnification from 1x to 20x
  • Mouse Wheel: Zoom in/out centered on your cursor position
  • Keyboard: Use + and - keys for zoom control

Pan Controls:

  • Click and Drag: Pan across the spectrogram when zoomed in
  • Arrow Keys: Navigate left/right when zoomed
  • Boundary Protection: Automatic limits prevent over-panning

Audio Playback Synchronization

  • Red Playhead Line: Shows current playback position in real-time
  • Click to Jump: Click anywhere on the spectrogram to jump to that time
  • Synchronized Updates: Spectrogram follows audio playback automatically

Settings Panel

Click the gear icon (⚙️) to access advanced controls:

Live Parameter Adjustment

Frequency Range:

  • Min Frequency: Lower bound of displayed frequencies
  • Max Frequency: Upper bound of displayed frequencies
  • Scale Mode: Choose between logarithmic, linear, or mel scaling

Display Quality:

  • Resolution: Balance between detail and performance (50-800 px/s)
  • Window (dB): Control the dynamic range of the display
  • Gamma: Adjust brightness and contrast
  • Percentile: Fine-tune noise floor detection
  • Smoothing: Reduce noise in the visualization

Species-Specific Profiles

iNatSpectro automatically detects the observed species and applies optimized settings:

Available Profiles:

  • General: Balanced settings for most wildlife sounds
  • Bat: Optimized for ultrasonic echolocation calls (15-120 kHz)
  • Bird: Enhanced for songs and calls with mel-scale perception
  • Frog: Specialized for amphibian vocalizations (150 Hz - 3 kHz)
  • Insect: Tuned for arthropod sounds (1-20 kHz)
  • Cetaceans: Optimized for marine mammal communications

Profile Features:

  • Automatic Detection: Based on iNaturalist taxon information
  • Manual Override: Select any profile manually if needed
  • Optimized Parameters: Each profile uses research-based settings
  • Persistent Settings: Your adjustments are saved per profile

Advanced Features

High-Resolution Analysis

  • Configurable Resolution: Up to 800 pixels per second for detailed analysis
  • Ultrasonic Support: Full spectrum analysis up to 384 kHz sample rates
  • Original Sample Rate Preservation: No downsampling during processing

Performance Optimization

  • Intelligent Caching: Coordinate calculations cached for smooth interaction
  • Automatic Safeguards: Canvas size limits prevent browser crashes
  • Progressive Rendering: Base resolution with high-res viewport on zoom

Tips for Best Results

Getting Started

  1. Let audio load completely before interacting with controls
  2. Start with 1x zoom to see the full overview
  3. Use species profiles - they’re optimized for different sound types
  4. Experiment with parameters to highlight features of interest

Troubleshooting Common Issues

No spectrogram appears:

  • Verify the observation has audio content
  • Check browser console for [iNatSpectro] messages
  • Try refreshing the page
  • Ensure extension permissions are granted

Poor visualization quality:

  • Try a different species profile
  • Adjust the frequency range for your audio
  • Increase resolution for more detail
  • Modify gamma and percentile settings

Performance issues:

  • Reduce resolution for long audio files
  • Close other browser tabs to free memory
  • Use lower zoom levels for initial analysis

Best Practices

For Scientific Analysis:

  • Document your parameter settings for reproducibility
  • Use appropriate species profiles for your taxa
  • Consider frequency ranges relevant to your species
  • Take screenshots of interesting features for reports

For Identification:

  • Compare spectrograms with known reference sounds
  • Look for characteristic frequency patterns
  • Use zoom to examine call structure details
  • Note temporal patterns and repetition rates

Next Steps

Now that you understand the basics, explore more advanced capabilities:

Getting Help

If you encounter issues or have questions: