Reading an audio spectrum analyzer or spectrogram tool—such as the popular SpectrumView app by Oxford Wave Research—requires understanding how sound is split into frequency, time, and intensity. These tools let you visually track how loud individual sound frequencies are in real time. Understand the Two Main View Modes
Most audio analysis tools, including SpectrumView, offer two distinct ways to look at your audio: 1. Spectrum Analyzer Mode (Frequency vs. Amplitude)
This view provides a real-time snapshot of the sound, acting like a constantly moving line graph.
Horizontal Axis (X-Axis): Displays Frequency measured in Hertz (Hz). Low-pitched bass sounds sit on the left side, while high-pitched treble sounds sit on the right side.
Vertical Axis (Y-Axis): Displays Intensity/Volume measured in decibels Full Scale (dBFS). The higher a peak reaches on the screen, the louder that specific frequency is. 2. Spectrogram Mode (Time vs. Frequency vs. Color)
This view displays a scrolling “heat map” of your sound, which allows you to trace how frequencies change over a period of time.
Horizontal Axis (X-Axis): Displays Time. The graph continuously scrolls from right to left as time moves forward.
Vertical Axis (Y-Axis): Displays Frequency. Unlike the analyzer mode, the lowest frequencies sit at the very bottom of the screen, and the highest frequencies sit at the top.
Color Scale: Displays Intensity. Instead of using peaks to show loudness, a spectrogram uses color. In SpectrumView, the scale typically spans from -96 dBFS (silence, represented by dark colors or black) up to 0 dBFS (maximum volume, represented by bright colors). How to Identify Specific Sounds
When looking at the moving charts, different audio sources create distinct visual signatures:
Whistling / Pure Tones: Appear as a single, isolated sharp peak in analyzer mode, or a single bright, narrow horizontal line in spectrogram mode.
Human Voice / String Instruments: Create a distinct “ladder” pattern of horizontal lines. The lowest line is the fundamental pitch you are singing or playing, while the perfectly spaced lines above it are its natural harmonics.
Clapping / Drums: Appear as sudden, sharp vertical blocks or streaks that slice across almost all frequencies at once, representing a sudden burst of wide-band noise. Interactive Tools and Navigation
According to the SpectrumView Official Help Guides, you can interact directly with the display to extract exact calculations:
Tap for Details: Tapping anywhere on the graph brings up a precise cursor showing the exact frequency in Hz and volume level in dBFS at that point.
Musical Notation: You can toggle settings so that tapping a point tells you the exact musical note in scientific pitch notation (e.g., C4 for middle C) and how many cents sharp or flat the tone is.
Pinch-to-Zoom: Use a finger pinch gesture to expand the frequency space vertically (spectrogram) or horizontally (analyzer) to inspect tight frequency clusters. SpectrumView – App Store