Korean J Otorhinolaryngol-Head Neck Surg.  2022 Jan;65(1):10-17. 10.3342/kjorl-hns.2020.01032.

Test-Retest Differences of the Speech Discrimination Score in Patients with Hearing Loss

• Lim T
• Oh JH
• Hwang J
• Joo JB
• Cho JE
• Kim JY

• KMID: 2524984
• DOI: http://doi.org/10.3342/kjorl-hns.2020.01032

Abstract

Background and Objectives
The diagnosis of hearing impairment is based on repeated audiometry, including pure tone audiometry (PTA), speech reception threshold test (SRT), and speech discrimination test (SDT). SDT results particularly show a wide discrepancy upon repeated testing, while malingering is suspected when having more than 12% difference between 3 individual SDT results. Therefore, in this study, we compared the proportion of malingering found in repeated SDT with that found in other audiometric tests and analyzed the characteristics of malingering group in order to reevaluate the current criteria of defining malingering.
Subjects and Method
We retrospectively assessed the audiometry results of 113 patients (226 ears) with hearing impairment. Each ear was divided into a malingering group and a true hearing loss group. The proportion of ears corresponding to each malingering criterion was compared using a chi-square test. An independent sample t-test was performed to identify the differences between the characteristics between the two groups.
Results
The number of ears that met the malingering criteria were 19 (8.41%) in PTA, 15 (6.64%) in SRT, and 75 (33.19%) in SDT. There was a significant difference in the proportion of malingering between the 3 hearing test modalities (p<0.001). There was no significant difference in auditory brainstem response, mean age and sex distribution between the malingering group and the true hearing loss group.
Conclusion
When conducting repeated SDT, there is a risk of misdiagnosing an actual hearing loss patient as a malingering patient under the current malingering criteria. Therefore, the current criteria on SDT requires reevaluation.

Keyword

Hearing loss; Malingering; Speech audiometry; Speech discrimination tests