If I had to picture a "light amplifier" I would think of a laser or something like a photomultiplier/image intensifier tube, not so much a microscope. Not sure

If I had to picture a "light amplifier" I would think of a laser or something like a photomultiplier/image intensifier tube, not so much a microscope. Not sure what a "sound magnifier" might actually be. There exist apparatuses called "acoustic lenses" but I don't believe they are used for applications that might be considered analogous to a microscope. Perhaps something like a stethoscope, or just a horn (think of the horn on early gramophones) might be considered as allowing humans to hear sounds that would otherwise be too faint to hear.