It’s a widget that shows what sound masking is and illustrates this using an example of one sound covering up another. It’s controlled via the keyboard or mouse, the mouse to click on the controls, the keyboard to adjust more quickly.
On the main canvas you see a graph: Loudness on the left, Frequency on the top. The masking threshold are the thick orange line. If your probe tone sits anywhere under this line it has been masked. Vertical bars represent the maskers. The circle is the probe. If the circle drop beneath the orange line the probe is difficult to hear.
How to Use the Widget
Settings is changed by dragging handles on the graph. The orange square is for moving the maskers in volume and frequency. The blue circle is for moving the probe. Below the graph, there’s a EQ notch option with a diamond handle that changes the center frequency of the cut.
There’s also keyboard available for nudging things around. The probe is selected by hitting the P button. Current maskers are cycled with the M button. When something is selected, use the arrow keys to change it. Left and right keys changes the element’s frequency. Up and down keys adjust the volume. For more precise changes hold the Shift key while pressing an arrow key.
On the left is a set of controls that allow you to fine-tune the scenario. There are level and frequency sliders for each masker. You can enter precise values in number boxes. The controls for the probe are identical. Overall output is controlled by a global volume slider. Note: this does not alter the relationship between the sounds.
With the EQ notch button you can apply a notch filter that reduces the masker but leaves the probe in place. You can turn on the notch and then adjust how wide the notch is, what frequency it’s centered at, and how deep it goes down. When you turn this on, the graph will automaticly update to show its impact on masking threshold.
There are three modes which can be heard in combination. Background noise only. Masker mode. The target tone only. Probe mode. Both together, this is where you hear the masking effect. These modes helps you understand how things interact, as well as isolate sounds.
It has preset buttons that load typical mixing scenario, such as a kick drum covering up a bass line, or vocals fighting against guitars. Clicking the preset resets your controls and the graph, giving you a starting point to experiment with.
In this test, we hide the masking curve on the graph. You are instructed to press a button (or key ‘1’ if it’s audible, ‘2’ if it’s not) and determine whether you can hear the probe or if it is covered up by another sound. Result and score are shown following every round of the game mode.
The challenge for rescue mode is to unmask a probe and repair it. In this case, you begin with the probe hidden from view. Your task is to use an EQ notch or adjust other controls until the probe can be heard. Is it rescued? Did you adjusted only minimally? The widget will let you know.
Clicking on the help button brings up a more detailed explanation of how it works. This is where I recommend visiting if you’re having trouble and want a deeper explanation of the science behind the widget. From here, you can also turn on fullscreen mode for a larger graph display.
Bring the probe near a masker and listen when it dissapears. Then pull it back out and listen when it returns. Tweak the EQ notch until you find that sweet spot where you clear a path. Try the presets where you’ll find other types of masking. Work through these situations and learn how to solve them.
Load a scenario from a preset then click on the probe. Listen as you move it across the graph. When it stops being audible, that is typically when you are near your target. Turn the notch of the EQ or whatever control down so it starts again. Keep playing with it till you have an idea of what each control do.