Dichotic Frequency Modulation in Preschool Children

Abstract

Undetected hearing difficulties in children can have lasting impacts on development. However, a significant number of children enter educational settings with subtle auditory processing deficits, often because current screening methods lack the sensitivity to detect them.

One such deficit is difficulty with temporal fine structure (TFS) processing. A promising method for addressing this gap is the assessment of TFS using dichotic frequency modulation (DFM) tests [1]. While DFM tests have been used in adult populations, no research currently applies this methodology specifically to preschool children. This study aims to create a developmentally appropriate DFM perception test to assess TFS sensitivity in preschoolers.

DFM is a hearing test in which two different frequency-modulated (FM) signals are presented simultaneously to each ear, creating the auditory illusion of a "moving" sound [2]. Low-frequency FM perception tests, including DFM, are commonly used in auditory neuroscience to evaluate TFS processing [1]. TFS plays an important role in speech understanding, especially in noisy environments, by helping listeners separate target and competing sounds [1].

Research examining TFS in children is limited [3]. Most existing studies focus on school-age children, leaving a gap in our understanding of TFS functioning in preschoolers. This study will explore differences in DFM detection thresholds between children aged 4 to 6 and adults using the same test. A quantitative analysis will be conducted on empirical data from 50 preschoolers with normal hearing, gathered through a developmentally adapted version of an existing test from the P.A.R.T. platform (available at: https://braingamecenter.ucr.edu/cognitive-perceptual-assessments/). The results will be compared to previously collected data from the adult population.

The child-friendly version of the DFM test will consist of four sound intervals represented by illuminated buttons. Children will be asked to identify the interval in which they perceive a “moving” sound. Since the current instructions assume reading ability, they will be replaced with a voice-guided, interactive tutorial featuring a detective bunny character to enhance engagement. Children may repeat the tutorial as needed until they understand the task. Testing will occur in a single session, with the tutorial followed by a shorter assessment phase.

Based on prior studies of frequency modulation detection [3], we expect that DFM detection thresholds in children will be higher than in adults.

References

‌[1] E. C. Hoover, B. N. Kinney, K. L. Bell, F. J. Gallun, and D. A. Eddins, “A Comparison of Behavioral Methods for Indexing the Auditory Processing of Temporal Fine Structure Cues,” Journal of Speech Language and Hearing Research, vol. 62, no. 6, pp. 2018–2034, Jun. 2019. doi: 10.1044/2019_jslhr-h-18-0217.

‌[2] K. L. Whiteford, H. A. Kreft, and A. J. Oxenham, “Assessing the Role of Place and Timing Cues in Coding Frequency and Amplitude Modulation as a Function of Age,” Journal of the Association for Research in Otolaryngology, vol. 18, no. 4, pp. 619–633, Apr. 2017. doi: 10.1007/s10162-017-0624-x.

[3] S. A. Flanagan et al., “Development of binaural temporal fine structure sensitivity in children,” The Journal of the Acoustical Society of America, vol. 150, no. 4, pp. 2967–2976, Oct. 2021. doi: 10.1121/10.0006665.