Evaluation of a synthetic version of the digits-in-noise test and its characteristics in CI recipients

Abstract

Objective

The goal of this study was the evaluation of a synthetic version of the Digits-in-Noise (DiN) in participants with normal hearing. Additionally, the basis characteristics of the DiN in CI recipients were investigated.

Design and study sample

Twenty participants with normal hearing and 21 CI recipients with a Nucleus®-System ran two to three adaptive and up to five fixed measurements. Afterwards the discrimination function was measured with fixed signal-to-noise ratios.

Results

All subjects were able to perform the DiN within three minutes per test run. The median speech reception threshold (SRT) for the NH was −8.1 dB_SNR, with a median steepness of 23%/dB_SNR. The median absolute test-retest difference in the NH group was 0.4 dB (range: 0 to 1.5 dB). In the CI group, the SRTs range from −6.6 to +12.4 dB_SNR with a median test-retest difference of 0.4 dB (range: 0 to 6.1 dB).

Conclusion

The synthetic DiN is a valuable complement of the audiometric test battery in CI recipients. The excellent applicability is also particularly helpful in poor performing CI recipients. With its small time exposure, it is a time- and cost-saving test, which could also be used at home via app to check the individual hearing success.

Keywords:

• Speech perception in noise
• Digits-in-Noise test
• cochlear implant
• people with normal hearing
• discrimination function

Acknowledgements

The authors thank Birgit Philips, Stefan Lievens, Obaid Qazi, and Bas van Dijk from the CTC Mechelen team for the technical support. The authors also thank Rachel More and Jan Willhaus for their editorial contributions to the manuscript.

Study registration

The study was pre-registered at the Deutsches Register Klinischer Studien (ID: DRKS00018819) in December 2019.

Disclosure statement

Thomas Hocke is an employee of Cochlear, the manufacturer of the technology described in the article. For several years, Miriam H. Kropp, Parwis Mir-Salim and Alexander Müller have also received travel grants for congress participations for other research projects through Cochlear Deutschland GmbH & Co. KG.

Additional information

Funding

This work was supported by Cochlear Deutschland GmbH & Co. KG under Grant [1219].