hi all and you Sheila
As Robert Eiichi has already commented MiniDisc is a perceptually-based lossy compression device so depending on the aim of your work it will be appropriate or not. If you just want to keep the intelligibility and a high quality recording of speech, that's ok, it keeps precise prosodic features. But if your aim is to process this signal to extract another features in a signal processing scenario I would recommend a DAT device to avoid any loss of information (objective).
hope it helps
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