As Dr. Sharma explained in our very first BrainHearing Network webinar, the audiogram alone is not enough to fully describe the consequences of hearing loss. To expand on this topic, we invited Prof. Jürgens to discuss additional measures beyond the audiogram to quantify a user’s ability to hear in noise and improve hearing-aid fitting and counseling.

The Audible Contrast Threshold (ACT™) Test: Predicting Hearing-in-Noise Ability and Improving Hearing-Aid Fitting

Prof. Jürgens began by illustrating how three individuals with identical audiograms and similar ages can have different abilities to understand speech in noise. How can we use this knowledge to personalize hearing solutions?

Although speech-in-noise tests are part of best-practice clinical routines, there has been no internationally standardized clinical method for hearing-aid fitting—until now. Speech-in-noise testing is often time-consuming and requires specialized equipment, especially for ecologically valid (realistic) assessments.

After years of research involving the Eriksholm Research Centre, the Interacoustics Research Unit, and Oticon, the Audible Contrast Threshold (ACT™) test was developed. Prof. Jürgens explained that the ACT test measures a patient’s ability to detect spectro-temporal modulations in noise, mimicking the modulations found in speech. The test uses a language-independent “siren sound,” following a simple procedure inspired by pure-tone audiometry (Zaar/Simonsen et al., 2023). The audiologist presents the sound intermittently, and the patient presses a button when they hear it. The results are given in dB nCL (normalized Contrast Level), with an average test duration of less than two minutes.

Clinical Study on ACT

Prof. Jürgens presented a large-scale clinical study conducted in collaboration with Japanese researchers. The study assessed ACT in a clinical setting and examined its correlation with patients’ hearing-in-noise difficulties and their hearing-aid needs. The dual-site study involved 108 patients (81 from Germany, 27 from Japan, aged 32-80) who used Oticon More hearing aids for six months while different “help levels” were tested (Zaar et al., 2024b).

The study found a strong correlation between ACT values and aided speech-in-noise ability, confirming previous research (Zaar et al., 2024a). Additionally, the study revealed variability in the benefits provided by MoreSound Intelligence™ (MSI) noise reduction settings. Some of this variability was explained by the degree of acoustic coupling measured via real-ear occluded insertion gain (REOIG). The more closed the acoustic coupling, the greater the benefit from noise reduction. Measuring REOIG in individual patients can therefore help optimize noise reduction benefits.

Overall, the study showed that ACT values and REOIG together accounted for 39% of the variance in noise reduction benefits. This means that ACT can help predict the optimal MSI noise-reduction setting for each individual (Santurette & Laugesen, 2023). Prof. Jürgens concluded that the ACT value “predicts how well a patient will perform with a well-fitted hearing aid.”

Key Takeaways

• The ACT test is a quick, language-independent assessment of hearing-in-noise ability, using a method similar to pure-tone audiometry.
• ACT is strongly correlated with and can predict how well a patient will understand speech in noisy environments with hearing-aid amplification.
• The benefit a patient receives from noise reduction depends on both acoustic coupling (REOIG) and their ACT value.

How ACT Can Elevate Your Clinic

ACT helps address the #1 complaint among people with hearing loss—difficulty understanding speech in noise. In just two minutes, ACT provides valuable insights into a patient’s hearing ability in noise and prescribes the appropriate level of assistance for challenging listening environments.

The results are seamlessly integrated into Oticon Genie 2, optimizing the fitting process and enhancing the overall hearing experience.

Learn more about ACT

Read our whitepaper on the research behind ACT

Learn about fitting and counseling with ACT

References

Santurette, S., & Laugesen, S. (2023). Audible Contrast Threshold (ACT™) - A language-independent diagnostic test to quantify real-life speech-in-noise ability and personalize help-in-noise settings in hearing aids. Oticon Whitepaper.

Zaar, J., Simonsen, L. B., & Laugesen, S. (2024a). A spectro-temporal modulation test for predicting speech reception in hearing-impaired listeners with hearing aids. Hearing Research 443: 443:108949. DOI: 10.1016/j.heares.2024.108949

Zaar, J., Simonsen, L. B., Sanchez-Lopez, R., & Laugesen, S. (2024b). The Audible Contrast Threshold (ACT™) test: A clinical spectro-temporal modulation detection test. Hearing Research 453: 109103. DOI: 10.1016/j.heares.2024.109103.

Zaar, J., Ihly, P., Nishiyama, T., Laugesen, S., Santurette, S., Tanaka, C., & Jürgens, T. (2023). Predicting speech-in-noise reception in hearing-impaired listeners with hearing aids using the Audible Contrast Threshold (ACT™) test. DOI: 10.31234/osf.io/m9khu.