One of the most significant changes brought about by the EU trade mark reform is the inclusion of new types of trade marks in the trade mark system. The category of sound marks was known before the trademark reform, but the main challenge for registration was the criteria of presentation. After the introduction of the EU trade mark reform, the absolute ground of non-distinctiveness may be the main obstacle, as the new rules ease the requirements for appearance, but the other basic condition for registration, the examination of distinctiveness, may be a challenge for the applicant. The ability of the consumer to identify the commercial origin of the product or service by means of a sound is a key factor in determining whether the sign is distinctive and able to become a registered trademark.