This interactive tool is a simple but useful little app that produces frequency sweeps (tones that slide up and down in pitch) that you can create and hear. Whether it’s for training your ear, testing out your setup, or just having fun experimenting with sound, this app put all the controls at your fingertips. You can use your computer keyboard for quick changes, or your mouse and trackpad.
It’s a graph with time along the horizontal axis, and frequency on the vertical axis. There are two handles (the start and end frequencies) which you can click and drag around to change pitch range. This creates a curve between the handles representing the variation in frequency. In Lab mode, you can adjust this curve by moving the handles. Your changes will update in graph in real-time.
How to Use This Tool
The four workspaces is accessed via a button on the top. By default, you’re in Lab, which is the workspace for designing custom sweeps. Next up is Game, which challenges you to guess starting note or hit a target frequency to stop the sweep. Or, you can choose Room, which plays a series of test tones so you can better understand how your listening environment (and speakers) sound. Finally there’s Hear, which plays a rising tone until it goes beyond your individual upper frequency limit.
Below the graph is what you use to manipulate the sweep details in Lab mode. Two frequency sliders let you set start and end points on your chosen scale. Another slider controls how long it takes for the sweep to reach its destination. If you need exact figures, there are number boxes adjacent to the sliders where you can enter them manualy.
A type button allows you to select either a linear or logarithmic sweep. The former adds the same frequency per second whereas the latter provides each octave with an equal time allotment. Using the shape button, you can select a continuous glide. You can also choose a ping-pong effect that goes up and then down again. Or, you can choose a stepped ladder where tones is held until the next one sounds.
The wave buttons control the waveform itself. Pure tones are sine waves, while others that are more brighter or more complex are square, sawtooth, and triangle waves. How loud it plays is controlled by the volume slider. With high volumes, particularly in the Hear mode, be aware that the tone can become pretty high pitched.
The repeat slider allows you to have multiple passes through a sweep with a pause between each one. This is controlled by the gap slider.
There are two types of challenges in the Game mode: Stop, where you hear a sweep play and hit the stop button when it passes through a target frequency; or Start, where you listen to a brief sweep and use the guess slider to guess what starting frequency was. Before you submit your guess, you can hear the sweep again as many times as desired. Your score is based on your best accuracy and streak. Settings for how wide the frequency range is and how fast the sweep travels adjust difficulty.
You could of also try it out in Room mode. Pick one of these presets which will play some standard test tones. You have the option to use stepped tones or glide. As it’s playing, click the Mark button when you hear anything that doesn’t sound right… Like maybe a rattle or buzz. The tool picks up frequency at that time. Then you can go back and see if there is something wrong with your room, acoustics, or speakers.
Use the Hear tool to find out which frequency you cut out. It has a tone that rises in pitch as it plays. Press play. Listen for when it appears to stop. Hit the Gone button, and the tool will record the frequency. Do the test again a few more times to ensure the number holds true. Keep in mind that it’s measuring your entire chain: volume level, speakers, etc., not just your ears.
You can control everything with your mouse or trackpad, or you can use your computer keyboard for faster adjustments. To play/pause, hit the space bar. To arm the start/end handles, hit S/E. With an arm handle, you can adjust its frequency up/down using the arrow keys (in semitone increments). Use the left or right arrow for finer control. Use Shift+arrow keys for larger jumps. Press X to swap start and end frequencies. Press L to toggle loop on or off. Select a waveform using 1-4. Press R to reset to defaults.
Clicking on the help button brings up a more detailed description of buttons. The fullscreen button expands the tool to fill your screen, giving you more room for the graph and controls. If you want to use the keyboard, you can also move around in the tool using the arrow buttons. The tool saves your settings so everything will be right where you left off next time.
For example, experiment with logarithmic sweeps to experience how it feels when the octave is even. Switch to Lab mode to narrow down a frequency and see how it works with the stepped shape. Begin at an entry-level difficulty in Game mode while getting comfortable and then move into a faster sweep. Pay extra close attention to any resonances in Room mode, which could signal problems with your speakers. Spend some time exploring the modes and find out what catches your ear.
To get started just hit the Play button in Lab mode to hear default sweep. You can drag the handles around to adjust the pitch range and then listen for the sound. Experiment with different waveforms and find the one that you like best. When you’re feeling confident, try the Room mode to test your setup, or the Game mode to test your ear. Feel free to mess around with the settings and see what happens, there’s no wrong way to use it.