Detection of ossicular chain pathologies using sweep frequency impedance with short-time stimulation and adaptive noise reduction

Conductive hearing loss typically results from ossicular chain abnormalities, commonly ossicular fixation or separation. While a precise diagnosis is useful for surgeons, distinguishing between fixation and separation before surgery is challenging. In our previous studies, we reported that sweep frequency impedance (SFI) effectively detects such middle-ear pathologies. However, due to the prolonged sound stimuli, SFI exhibited weaker resistance to noise. In this study, we introduce a novel method using short-time stimulation and adaptive noise reduction to improve SFI performance. The method was applied to both healthy individuals and patients, and a support vector machine was employed to evaluate its accuracy in distinguishing fixation and separation in clinical practice. The proposed SFI yielded results consistent with the original SFI meter but significantly shortened the evaluation time to within 200 ms. Classification results indicate that the SFI achieved accuracies of 98% and 83% for detecting ossicular separation and fixation, respectively. In contrast, such accuracies of traditional tympanometry were 70% and 49% for the separation and fixation. Additionally, the study indicates that gentle lullabies can serve as effective acoustic stimuli. These results suggest that our new SFI has potential for middle-ear testing across all age groups, from newborns to the elderly.