Sonance

Sound You Can See! Sonance is an Audio Spectrum Analyzer & Spectrograph app, a Music Player, and a Decibel Meter. It analyzes sound from songs played by the music player, from the built-in microphone, or from a Line In input device, and displays the results in three separate views. The music player plays songs from the local macOS Music app library. These songs must be local to the Mac where Sonance is installed — Home Sharing from another Mac is not currently supported by the macOS Music app Library Framework. Internet streams and internet radio stations are supported in a limited fashion: they will play, but raw audio data isn't always available for those sources, in which case the displays only work through what the microphone picks up. The Waveform view displays the raw input signal as a continuous wavy line, where each wave is a pulse of sound. Decibel level is also displayed. The Spectrum view displays the frequency distribution as vertical bars. Each bar represents a group of frequencies, with height indicating the strength of those frequencies within the audio signal. The Spectrogram view displays a two-dimensional view of audio frequencies over time. Each pixel represents a group of frequencies, with color indicating strength. Vertical rows represent different frequencies; horizontal columns represent time. Frequencies range from 0 Hz to 48,000 Hz (48K) — half the 96,000 samples-per-second maximum sample rate of a MacBook Pro's internal microphone. Displayed frequencies are always half the input device's sample rate, which can be 44,100, 48,000, 88,200, or 96,000 samples per second. For music played via the music player, the range depends on the sample rate of each song — most fall between 0 and 22,050 Hz, half the 44,100 samples per second used in CD recordings. Since Sonance also uses the microphone, any sound it can pick up is analyzed and displayed — play music on your computer, or use a different sound system entirely, and see the frequency distribution, spectral density, and waveform. WAVEFORM VIEW Adjust Input Gain (waveform height) and Display Width on the fly, and freeze the display. The horizontal scale represents time in seconds; the vertical scale shows the audio sample value. For the 32-bit floating point audio codec, values range from -1.0 to 1.0. Input levels differ greatly between recorded audio and the microphone. Sonance has independent settings for both modes and switches between them automatically — affecting Input Gain on the Waveform view, vMag on the Spectrum view, and Sensitivity on the Spectrogram view. SPECTRUM VIEW Adjust Vertical Magnification (vMag) and Horizontal Zoom (hZoom) on the fly. Vertical Magnification adjusts bar height; Horizontal Zoom lets you zoom in on specific frequencies. After changing hZoom, use the scrollbar to pan across the full spectrum. SPECTROGRAM VIEW Adjust the Sensitivity slider to control color intensity, and the Vertical Zoom (vZoom) slider — similar to hZoom on the Spectrum view — to zoom in. Use the scrollbar to pan across the full spectrum once zoomed, and the freeze button to freeze and unfreeze the display. Full-screen display is available for all three views: select View > Full Screen Display, click it from the View menu, or use Command-F to put the active window into full-screen mode. You can also record a spectrogram for later viewing — select View > Spectrogram Recording Control Panel to start and stop recording and save your data.