In-situ adaptive speech enhancement using directional microphone applied to magnetic resonance imaging

Magnetic resonance imaging (MRI) is increasingly applied for medical diagnosis and biomedical research; however, the acoustic noise during the MRI operation remains one of the major concerns. In particular, speech communication through intercoms from patients to MRI operators is severely contaminated by the annoying noise, and requires treatment for improving the intelligibility. This study proposes an enhanced adaptive speech enhancement (ASE) system, utilizing the idea of a differential directional microphone for measuring and distinguishing the reference and desired signals, for the MRI environment to improve the speech communication. Hence, the adaptive filter is expected to remove the periodic MRI acoustic noises with limited distortion on the recovered speech signals. In-situ experiment was conducted to evaluate the system performance. Results show that the speech signal is noticeably recovered after treated with the ASE system. Furthermore, a non-adaptive spectra subtraction method is also adopted to process the abovementioned results such that additional reductions were achieved for the non-coherent MRI noises.