Earful v1.0 is the initial beta release of this software. Use at your own risk!


Download Earful for Windows

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What is it? And a WARNING!

Earful is an app designed to measure and evaluate the lower threshold of hearing across a frequency spectrum. It is designed to run on Windows and support ASIO, WASAPI, and Direct Sound audio devices. Use with headphones is recommended for greater accuracy and noise elimination.

The app is free to use, but to use it, you must agree to do so AT YOUR OWN RISK ONLY. Make sure that the volume settings are set such that any loud sounds played through your system will not damage your equipment or your hearing! This is important. Set the frequency range in Earful correctly, and also specify the maximum volume setting at a low number to avoid surprises (default is -20dBFS).


  • Pick your own frequency range for the test
  • Specify any number of logarithmically spread points to test along the frequency axis
  • Compare your results to others, compare to your older tests to check for changes, or compare to any of the industry standard, published curves
  • Test with a single tone, a warble tone, or a band-limited white noise
  • Using a simple text format supported by REW, so the result can be loaded into that tool directly
  • Supports ASIO, WASAPI exclusive/shared, and Direct Sound device drivers
  • Display in dB SPL or in db FS with configurable dBSPL calibration
  • Apply a flat calibration curve to account for variations in headphones or speakers

How to use

The mission, should you chose to accept it, is to move the volume control up and down in small increments until you find the spot where the sound produced by Earful disappears or becomes inaudible. When you find this place, move up one step, and that will determine the lowest audibility threshold for that frequency. Repeat for all the points across the spectrum, and you’ll get your entire threshold curve!


  • Start by selecting the desired audio output device from the drop-down list
  • Use headphones or speakers, although headphones are probably a better way to determine your lowest hearing threshold
  • Whatever device you chose: MAKE SURE THE VOLUME IS TURNED DOWN on any preamp or DAC to a level that doesn’t allow excessively loud sounds. Earful will never exceed the maximum volume setting specified on the main window, but device drivers and Windows glitches can cause very loud sounds to be reproduced. BE CAREFUL.
  • Select the desired type of sound (Single Tone, Warble, or White Noise). Single Tone is a simple sine wave, similar to what was used for Fletcher-Munson curves and ISO0226 standard
  • Check that the frequency range is set to what it is you want to test. You can specify smaller or larger bandwidth for testing, default is 20Hz-20kHz
  • Enter more data points if you’d like a more fine-grained test. Default is 32 and this means you’ll have to repeat the process of searching for audibility for each of the 32 tones to complete the test
  • Make sure the start volume is set low enough not to blow your speakers or subwoofer. -60dBFS is the default setting here.

Start the test

  • Press the play button in the middle of the four arrows to start the test. The test will start with the lowest frequency you specified, at the start volume you selected.
  • At any time, press the Pause button to stop playing sounds
  • Move to next or previous frequency in the test by pressing Left or Right arrow buttons. The frequency plot will highlight the point where you are in the test as you do this
  • To jump quickly to any point in the test, use the horizontal slider control labeled Current Point
  • When at the desired test frequency, Earful will automatically start issuing the selected sounds, interrupted by a short period of silence
  • If you can’t hear the tones, try increasing the volume by pressing the Up arrow. If the tones are loud, press the Down button until they become barely audible
  • You can use the volume slider on the right to quickly adjust the volume if the current setting is too far off. BUT PLEASE BE CAREFUL WHEN ADJUSTING UP, as you may accidentally jump to a point that’s very loud. The slider will not allow setting the volume above the maximum setting specified at the start
  • Keep pressing up or down buttons until you get to the point where the tones are hard to hear. If you push the down arrow once at this point and the tones become inaudible – congratulations! You’ve found the lowest threshold of hearing for this frequency. Move on to the next frequency by pressing the Right button.
  • You can always go back and re-test any of the points you’ve already measured, just press the Left button to go back.
  • Continue through all the points in the test. When completed, you’ll see your lowest audibility threshold curve in the plot.

After the test, data handling

  • At this point, you can save the curve for later comparison, sharing with others, or for future reference. Click on Save button on the right and pick a descriptive file name.
  • Earful uses the standard frequency response text file format used by REW, and so the output of Earful measurement can be loaded directly into REW, or vice-versa.
  • To compare two curves, or the one you just captured to another, click on load button and select the previously saved curve. You’ll be able to load it into Data Set 1, which is the measurement data set, or Data Set 2, which is the comparison data set. A couple of comparison files are installed with Earful: Fletcher-Munson standard curve and ISO0226-2003. These represent average lower threshold of hearing across multiple people that were studied.
  • Normally the second data set it automatically indexed to the lowest value in your measured data set 1. If you’d rather to index them manually, please use the + and - adjustment buttons to move the second data set up or down by one volume step size. If you check the Auto button, the automatic indexing at the lowest value will be restored.
  • Clear All button on the right allows all the data to be cleared from Earful to start over. Please save any data that you may have captured up to this point, as it will be lost.

That’s it for now! Hope you find Earful useful, and looking forward to your feedback.

Changes in 1.0.7

  • Added support for applying headphone calibration curves for flat response (a pure frequency response of a microphone coupled to the headphones)
  • Added Shift-Click to directly select any point on the plot
  • Added Shift-Left/Right/Up/Down to control selecting frequency and setting volume directly from the keyboard
  • Fixed exceptions when ASIO or WASAPI drivers are not supported (for example, under Wine on Linux)
  • Fixed data points being set to the previous point volume setting when the actual value is -120dB

Changes in 1.0.6

  • Fixed labels not cleared on the graph after the data is cleared
  • Fixed WASAPI exclusive mode not turning on for some audio drivers
  • Fixed automatic switch between shared/exclusive mode when the checkbox is changed
  • Added a little delay when reacting to previous/next buttons or the slider to reduce sound glitching
  • Fixed first data point value not set correctly in saved data after reloading on start-up of Earful

Changes in 1.0.5

  • Fixed many audio threads created when moving around the chart
  • Added screen shot button
  • Added current step counter display
  • Fixed clearing the first data point when data is cleared by setting volume slider to starting volume
  • Added saving current settings on exit and reloading on start

Changes in 1.0.4

  • Speeded up audio signal generation for slower processors

Changes in 1.0.3

  • Added dBSPL display option
  • Added SPL Meter calibration
  • Changed data file loader to use proper regional settings for decimal separator

Changes in 1.0.2

  • The initial public beta release of Earful