Development and validation of the Italian digit-in-noise test

Area of Science:

• Audiology
• Speech-language pathology
• Medical technology

Background:

• The Digits-In-Noise (DIN) test is a valuable tool for assessing speech recognition in noise.
• A validated Italian version of the DIN test is needed for clinical and research applications.
• Current assessment methods may not always allow for independent ear evaluation or efficient administration.

Purpose of the Study:

• To validate the Digits-In-Noise (DIN) test for the Italian language.
• To develop an Italian DIN test version capable of independently assessing both ears.
• To ensure the test maintains acceptable administration times for practical use.

Main Methods:

• Italian digits 0-9 were recorded and normalized for equal recognition probability.
• An iOS application (APP) was created for bilateral, independent ear testing using digit triplets in noise.
• A novel adaptive procedure was implemented to optimize the determination of Speech Reception Threshold (SRT).

Main Results:

• Normative data were established using 45 normal-hearing and 62 hearing-impaired individuals.
• The validated test achieved threshold values for normal hearing consistent with existing literature.
• Threshold values aligned with World Health Organization (WHO) hearing loss categories were identified.

Conclusions:

• A validated Italian Digits-In-Noise (DIN) test for individual ear SRT assessment has been developed.
• The adaptive algorithm optimizes test efficiency and duration for both ears.
• The test allows for autonomous administration via standard iOS devices (tablets/smartphones).