The Audible Contrast Threshold (ACT) test is a new audiological test that helps determine the patient’s ability to understand in noise with hearing aids on. This is a novel approach to speech understanding in noise as ACT uses the patient audiogram to custom generate a signal to approximate aided speech results. The custom generated stimulus allows the test to be performed under headphones without the need of using hearing aids to obtain the aided speech-in-noise setting. The goal is to be able to perform the ACT test inline with the traditional audiometric testing battery that clinicians perform. This allows for an ideal workflow and additional information to be determined about the patient. 

The ACT stimulus is a spectro-temporal modulated signal which correlates to listeners’ speech reception performance1. This stimulus is not a speech-based signal, which allows any language speaker to be able to perform the test at equal levels to others. The language independence of the ACT tests makes it a valuable tool for any clinician to have at their disposal. This will allow clinicians to accurately measure a patient’s aided speech-in-noise performance no matter their native language.  

Inside the MedRx audiometry module, clinicians can find ACT as a supplemental test similar to Word Recognition. The ACT test uses a wave stimulus presentation paradigm which is continuous noise bursts in which the clinician can inject the ACT stimulus at any time. The patient simply pushes the push button when they hear the stimulus and the software automatically scores the response and prepares the next presentation level. The test is a quick 2- to 3-minute test performed binaurally and results in a contrast level loss which is similar to signal-to-noise loss. To receive a demonstration of the test and the ACT stimulus, clinicians can call a MedRx trainer at 888-392-1234 to schedule a demo.

Additionally, the ACT results are saved inside the data files that MedRx saves to a Noah database. Saving the data in this way allows hearing aid manufacturers to access the ACT results from the saved records. The result can then be used by a hearing aid manufacturer to customize the patient’s hearing aid based on their aided speech-in-noise performance. This creates a more custom fit for a patient and may result in higher satisfaction.

The new ACT test is available in new MedRx audiometers and comes as standard. Previously purchased audiometers (MedRx Studio compatibility required) can upgrade their equipment to have access to the test as well. Those interested can contact [email protected] to learn more about adding ACT or purchasing an audiometer with ACT.

  1. Toward a clinically viable spectro-temporal modulation test for predicting supra-threshold speech reception in hearing-impaired listeners – ScienceDirect

Featured image: Audible Contrast Threshold (ACT) testing is available in MedRx audiometers. Photo: MedRx