Improving the efficiency of the digit triplet test using digit scoring with variable adaptive step sizes

Area of Science:

• Audiology
• Speech-Language Pathology

Background:

• The Flemish Digit Triplet Test (DTT) is used to assess speech reception thresholds (SRT).
• Improving the efficiency of the DTT is desirable to reduce testing time.

Purpose of the Study:

• To investigate modifications of the DTT to enhance its efficiency.
• To evaluate the impact of low-pass filtered noise and variable adaptive step sizes on DTT performance.

Main Methods:

• Speech reception thresholds (SRT) were assessed in 68 adults with hearing impairment.
• Test-retest reliability and correlation with pure tone averages (PTA) were evaluated.
• Different recognition probabilities (79%, 57%, 35%) and scoring methods were compared.

Main Results:

• Low-pass filtered noise did not improve test-retest reliability or SRT-PTA correlation.
• Digit scoring with adaptive step sizes targeting 79% recognition (D79) increased test-retest reliability.
• Lower recognition probabilities (57%, 35%) resulted in worse reliability and SRT-PTA correlations.

Conclusions:

• The D79 modification enhances test-retest reliability compared to standard DTT methods.
• This improved reliability allows for a similar accuracy with fewer trials, reducing overall test duration.
• The DTT can be made more efficient for clinical audiology practice.