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Voice Thickener (コエカタマリン Koekatamarin) is a gadget that resembles a small thermos containing violet liquid medicine. It is commonly used in the Doraemon series. When used, it turns the user's shouts into solid objects shaped like the words they shout.


When a person drinks the medicine, it solidifies their speech by firing a physical manifestation of the content. For say, if the person shouted 'Ya!', a corresponding Katakana letter 'Ya' () will come out. Meanwhile, İf user shouts 'Ro' it will became an object shaped like "". The letter's velocity is slightly slower than sound, and it does bounce off or be absorbed into hard surfaces and soft surfaces respectively (because their properties is rather similar to sound). The letters can maintain their velocity and momentum for a surprising amount of time and so may serve as transportation on their own.

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  • In the US English Dub, this gadget is referred to as, "The Sonic Solidifier", and is shown to only use the letter O.
  • So far, the Sound Medicine makes the user shouts out solid Katakana letters, the medicine is probably made that way.
  • Mostly used characters are Wa ' ワ' and Ro 'ロ'.
  • According to Doraemon in the 1979 anime, Voice Thickener is not actually bitter or spicy.
  • In the 1979 anime, the effect lasts for 30 minutes, but in the 2005 anime, it lasts longer.
  • Its Japanese name 'コエカタマリン' is possibly derived from 'コエ' (Sound) and 'カタマラ' (Harden).