|Meatloaf references mean I'm both old AND nerdy.|
In Acoustics terms, "band" refers to a span of frequencies.
Sound frequency is a measurement of how often the soundwave repeats itself, like so:
Each of these waves represents one sound frequency, like one key being played on a piano. If we were to play multiple notes on a piano at the same time, the bandwidth is measured as the difference between the highest key/frequency and the lowest key/frequency. Here are some extreme examples from hydrophone recordings:
Broadband. This is a spectrogram of a hydrophone hitting the side of a boat as it comes out of the water. Frequency is on the y axis, time is on the x axis, and the more "hot" the color is, the louder the sound. These sounds are considered broadband because they contain a large range of frequencies. On a spectrogram, the broadest band is a vertical line across the entire screen. The width of the vertical line will vary depending on the length of the sound.
Narrowband: This is the spectrogram of a dolphin whistle. Axes the same as before. As you can see here, the whistle only uses a few frequencies at a time, so it looks like a narrow, almost horizontal or diagonal line.
What about this killer whale call, with a bunch of harmonics? On one hand, it's made up of a bunch of narrowband signals, but on the other hand, it covers a wide range of frequencies. It's a hard call, and probably depends on the context and the scientist.
Bandpass filter - Allows a specific range of frequencies pass though a sound filter
1/3 Octave Band: A range of frequencies that is defined as 1/3 of an octave
One Man Band: What a grad student in acoustics looks like when they are trying to learn programming, engineering, and statistics all at the same time.