The phrase "field mouse ear" isn't a common phrase in English. It could imply the ear of a field mouse or be interpreted metaphorically.
खेत के चूहे का कान
English Usage: The field mouse ear twitched at the softest sound.
Hindi Usage: खेत चूहे का कान सबसे हल्की आवाज़ पर भी फड़क गया।
khet chuhe ka kaan, khet chuhā ka kān, khet chuha ka kaan, khet chuhā kā kān
