The effect of harmonic training on speech perception in noise in hearing-impaired children

Speech perception in noise is a highly challenging situation experienced by hearing-impaired children (HIC). Despite advances in hearing aid technologies, speech perception in noise still poses challenges. Pitch-based training improves pitch discrimination and speech perception and may facilitate concurrent sound segregation. Considering the role of harmonics in the analysis of concurrent sounds, we performed a harmonic assessment, examined the role of harmonic training in the rehabilitation of moderate-to-severe HIC, and investigated its effect on their speech perception in noise.

The participants were 57 normally hearing children (NHC) with a mean age of 7.73 ± 1.57 years and 18 HIC with a mean age of 7.94 ± 1.47 years. The two groups were compared in terms of harmonic assessment, the Pitch Pattern Sequence Test (PPST), the Consonant-Vowel in Noise (CV in noise) test, and the Bamford-Kowal Bench (BKB) test. Subsequently, the HIC underwent harmonic training, and the results of the pre- and post-harmonic training assessments were compared.

HIC displayed poorer harmonic discrimination than NHC at all harmonics (P < 0.05). They also showed lower scores in PPST, CV in noise, and BKB tests compared to NHC (P < 0.05). Harmonic training led to HIC's better performance in harmonic assessment, PPST, and CV in noise test (P < 0.05). However, the BKB test results pre- and post-training did not significantly differ (P > 0.05).

Harmonic training plays a significant role in improving the HIC's temporal processing of the PPST and CV in noise test; therefore, it can serve as a rehabilitation method to enhance temporal processing and auditory scene analysis.