iCallsign Professional Edition is designed to improve speech recognition under difficult listening conditions. Many individuals can hear the voice of a conversational partner but have trouble understanding what is being said. These types of listening deficits are often made worse when the voice of the conversational partner is mixed with noise or the sound of other voices.

iCallsign provides a structured training program to improve speech recognition in complex listening environments. It is directed toward anyone with conversational deficits, but it is designed in particular for individuals who are learning to maximize the performance of hearing aids or cochlear implants.

Training is based on the coordinate-response measure of speech recognition.

          “Ready, Arrow, go to Red 3 now...”

This sample sentence instructs a listener who designated with the callsign Arrow to go to the coordinates Red 3. Your objective is to respond by tapping the color then number of the coordinates that are delivered with your callsign. You should ignore coordinates that are delivered with other callsigns. By default, your target sentences are always spoken by the same male talker and begin with the callsign Arrow.

When the auto training procedure is selected, the loudness and number of distracting sentences will gradually increase to make the task more difficult. The current training level is indicated by the progress bar on the control panel at the bottom of the test screen.

Once you are familiar with the coordinate response measure, you should explore other target voices and call signs. These settings are accessed by tapping the SETTINGS icon on the control panel.

The Automatic Training procedure can be turned on or off. The distractor loudness level can be manually increased or decreased. The voice and call sign of the target talker can be changed by tapping CHANGE TARGETS. The voices, callsigns, and number of distractor sentences can be changed by tapping CHANGE DISTRACTORS. Default parameters are restored by pressing the RESET button on the control panel of the test screen.


iCallsign should be used with Apple earbuds under quiet conditions.