Spectrum Analyzer

Start the analyzer the same way as the meter: allow microphone access, and the display begins updating live. The bar/line view shows relative energy across the full audible range on a logarithmic frequency axis — logarithmic because that matches how pitch actually sounds to the human ear, where the jump from 100 Hz to 200 Hz feels like the same musical interval as 1,000 Hz to 2,000 Hz.

Switch to the 1/3-octave view for a steadier, more traditional acoustic-engineering read: instead of thousands of raw FFT bins, it groups energy into standard 1/3-octave bands, the same resolution most professional room-acoustics and noise reports use. Peak Hold freezes the loudest value seen in each band so short transients don't disappear between frames; Freeze pauses the whole display for a closer look, and Resume picks live updates back up.

The dominant frequency reading identifies the single strongest pitch present right now, refined with parabolic interpolation between FFT bins for better precision than the raw bin spacing alone would give, and shown alongside its nearest musical note and how many cents sharp or flat it sits from that note's standard pitch.

A spectrogram (waterfall) view plots frequency against time, with color showing intensity — useful for watching how a sound's frequency content changes over several seconds, such as a siren sweeping or a motor speeding up.

Musicians and audio engineers use it to tune instruments by ear-verified frequency, or to check a room or speaker for problem frequencies before a recording or performance. It's a fast way to hunt down an electrical hum (commonly a sharp, sustained peak at 50 or 60 Hz and its harmonics) or feedback building up before it becomes audible as a howl. It also works as a rough listening-test tool: play a known test tone through a speaker or headphones and check that the peak shows up where it should.