Prediction of pure tone thresholds using the speech reception threshold and age in elderly individuals with hearing loss

Abstract

Objective: Early detection and effective management of hearing loss constitute the key to improving the quality of life of individuals with hearing loss. However, in standardized pure tone audiometry, it is sometimes difficult for elderly patients to understand and follow all instructions. Audiologists also require time, expertise, and patience to ensure that an elderly can identify the faintest levels of stimuli during a hearing test. Therefore, this study aimed to devise and validate a formula to predict the pure tone threshold at each frequency across 0.5-4 kHz (PTTs) using speech reception threshold.

Methods: The 1226 audiograms of hearing-impaired individuals aged 60-90 years were reviewed. The random sample function randomly assigned 613 participants to the training and testing sets each. A linear model was created to predict the PTT value at each frequency based on variables significant at all frequencies across 0.5-4 kHz. The adjusted-R2 value was considered to indicate the performance of the predictive model. Pearson's correlation coefficient was used to describe the relationship between the actual and predicted PTT at 0.5, 1, 2, and 4 kHz among the testing set to measure the performance of the proposed model.

Results: The predictive model was devised using variables based on the speech recognition threshold (SRT) after adjusting with age in the training set. The overall prediction accuracy demonstrated a higher adjusted-R² ranging from 0.74 to 0.89 at frequencies of 0.5, 1, and 2 kHz, whereas a low percentage of explained variance was observed at 4 kHz (adjusted-R² = 0.41). This predictive model can serve as an adjunctive clinical tool for guiding determination of the PTTs. Moreover, the predicted PTTs can be applied in the hearing aid programming software to set appropriate hearing aid gain using standard prescriptive formulas.

Keywords: Elderly; Predictive model; Pure tone threshold; Speech reception threshold.

Fig. 1

Pearson’s correlation coefficient describing the relationship between the speech reception threshold (SRT) and pure-tone threshold (PTT) at 0.5, 1, 2, and 4 kHz among training set

Fig. 2

Pearson’s correlation coefficient describing the relationship between the actual and predicted pure-tone threshold (PTT) at 0.5, 1, 2, and 4 kHz among testing set