Beyond the audiogram: ACT™ is a new standard for speech-in-noise prescription
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 follow up on this topic, we invited Prof. Jürgens to talk about what additional measure we can use beyond the audiogram to quantify the user’s ability to hear in noise and provide better hearing-aid fitting as well as counselling.
A dive into Prof. Jürgens talk “The Audible Contrast Threshold (ACT™) test: a novel test to predict hearing-in-noise ability and guide hearing-aid fitting”
Prof. Jürgens started his talk with the example of three people having the same audiogram and a similar age, but different abilities to understand speech in noise. How can we use this additional knowledge about patients’ hearing-in-noise abilities to offer personalized help accordingly? Although speech-in-noise tests are often part of best-practice routines in the clinic, until now there hasn’t been an internationally standardized clinical method that could also be used for hearing-aid fitting. Additionally, measuring speech-in-noise is time consuming and, in most cases, it requires additional equipment, especially when an ecologically valid (i.e., realistic) set up is needed.
With this motivation in mind, and 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 the ability to detect spectro-temporal modulations in noise, which mimick the modulations contained in a speech signal. This signal, used in the ACT test, resembles a siren sound. The ACT test is language-independent and can be measured with a fast procedure inspired by pure-tone audiometry (Zaar/Simonsen et al., 2023). During the ACT test procedure, the audiologist presents the “siren sound” intermittently, and the patient is instructed to press a button once he/she hears this special sound. The test results are given in dB nCL (normalized Contrast Level). The average test duration is less than 2 minutes.
After explaining the details of the ACT test, Prof. Jürgens focused his talk on presenting a large-scale clinical study, in which he was principal investigator in collaboration with researchers from Japan. The goal of the study was to assess the novel ACT test in a clinical context and to understand how it relates to patients’ difficulties in terms of hearing in noise and their resulting needs in terms of hearing-aid processing. A dual-site study was conducted, where 108 patients (N=81 from Germany; N=27 from Japan; 32-80 years old) were fitted bilaterally with Oticon More and used the hearing aids for a period of six months, during which different “help levels” were tested (Zaar et al., 2024b). A help level is defined as the amount of support that the hearing aid will provide in noise – depending on the settings of MoreSound Intelligence™ (MSI). The patients’ preference for the different help levels was collected. The ACT test and an ecologically valid speech-in-noise test were also conducted before and after the field trial. The study revealed that the ACT value strongly correlated with the aided speech-in-noise ability, in agreement with previous findings (Zaar et al., 2024a). The results also showed a large variability in terms of the benefit that the MSI help-in-noise settings could offer patients. Interestingly, some of this variability could be explained with the closedness of the acoustic coupling measured via real-ear measurements (REM). In other words, the more closed the acoustic coupling (REOIG: real-ear occluded insertion gain), the higher the benefit that noise reduction could provide for speech in noise. Hence, measuring REOIG in individual patients can provide high value for understanding individual benefits of noise reduction. Overall, the findings of this study showed that including both REOIG and the ACT value to explain noise reduction benefits could account for 39% of the variance in the data. These results indicate that the ACT value is an indicator of how high the MSI help-in-noise setting should be to support the person the best possible way (Santurette and Laugesen, 2023). Prof. Jürgens concluded his talk by saying that the ACT value is “a prediction of how the subject will perform with a well fitted hearing aid”.
Take-home messages from the talk
- The ACT test is a quick audiological test of hearing-in-noise ability, which is conducted using a similar procedure as applied in pure-tone audiometry. The ACT value provides information about the patient’s hearing deficits beyond the audiogram.
- ACT is correlated with, and thus predicts, the hearing-in-noise abilities of hearing-impaired listeners provided with hearing-aid amplification, as measured through a realistic speech test with multiple interfering talkers.
- The amount of speech-in-noise improvement that patients gain from noise reduction is primarily connected to the closedness of acoustic coupling (REOIG) and ACT.
Learn more about the benefits of ACT in your clinic
ACT lets you address the #1 complaint for people with hearing loss – hearing speech in noise. ACT quickly provides you with language-independent insights into users’ hearing ability in noise, and instantly prescribes the level of help they need in challenging listening environments.
Invest two minutes on average to elevate your fitting process and optimise the hearing experience for your clients and help them get the most out of their hearing aids. With ACT, your test results are seamlessly integrated into Oticon Genie 2, for a quick and personalised hearing aid fitting.
Learn more about ACT
Read our whitepaper covering the extensive research behind ACT
Learn about fitting and counselling 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 personalise 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, October 16). Predicting speech-in-noise reception in hearing-impaired listeners with hearing aids using the Audible Contrast Threshold (ACT™) test. https://doi.org/10.31234/osf.io/m9khu