threshold shift threshold shiftan increase (worsening) in the threshold of hearing for an ear at a specified frequency Related Articles: Reference List: Animals and SoundHearing Loss in MammalsHearing Loss in FishesHow is sound used to protect marine mammals?Tutorial: Mammals – Hearing lossMarine Mammal Hearing AttenuationOcean Sound PoliciesPile drivingHearing Loss Advanced TopicTutorial: Hearing Loss Chris Knowlton2017-02-26T20:10:02-05:00