Audio Spectrum Viewer is an easy to use app which will show the frequency content of your live audio environment in an easy to understand waterfall / spectrogram. This tool can be used to analyze the performance of speakers and sound systems, and to create audio fingerprint images of environmental sounds such as bird songs and other animal sounds. Audio Spectrum Viewer is a powerful tool with user-selectable gain, sample rate and other parameters to optimize for a particular setting. Spectrograms can be saved to the camera roll with a timestamped and customizable caption and the audio clips can be saved for later playback. Audio can be captured in the background so you can simultaneously take photos of birds while analyzing their sounds.
Usage tips:
Tap the pause/play button on the toolbar to stop and start the capture and scrolling visualization.
Tap the Bars icon to turn on/off the real time bar graph below the spectrogram.
Tap the save icon to save the current spectrogram display to the camera roll, as well as optionally add a caption to the image and save the audio clip which is visualized. Saved audio clips can be retrieved or played back from the “Files” app built into iOS.
Tap the settings icon to change sample rate, scroll speed, low frequency zoom and other settings.
Adjust the gain slider on the main toolbar to accommodate quite or loud sounds. If the capture is paused, adjusting the gain slider will update the visualization for the already captured sound clip.
The white vertical lines on the spectrogram each represent 1000Hz frequency steps. The leftmost white line is 1000Hz, the second line is 2000 Hz, the third line is 3000 Hz, etc.
The horizontal lines on the spectrogram each mark one second of sound captured.
The amount of audio captured for the visualization can be controlled on the settings screen with the sample rate, sample buffer length, and scroll speed settings. A smaller sample buffer length will scroll faster.