Spectral Eye for the iPad, iPhone, and iPod Touch
Spectral Eye is a free sound analysis tool from Secret Base Design
Sound wave forms can be decomposed into individual sine waves by using a Fast Fourier Transform (FFT). This is frequently used by musicians and sound engineers to analyze the performance of microphones and speakers, as well as to study the tone of musical instruments.
The traditional way to visualize an FFT is with a frequency chart. Spectral Eye takes this information, and wraps it as a spiral, so that frequencies that are an octave apart are lined up as rays from the center of the display.
The app performs analysis in real time on audio. The app was initially developed as a debugging tool, used while working on some of our other apps. We decided to make this freely available to anyone who might want to use it. The app supports the iPad, iPhone (including the iPhone 5), and iPod touch. The current version also allows freezing of the display to look more closely at sound frequencies.