Digital Audio Broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services in many countries around the world, defined and promoted by the WorldDAB forum. The standard is dominant in Europe and is also used in parts of Africa, Asia and Australia; other worldwide terrestrial digital radio standards include HD Radio, ISDB-Tb, DRM, and the related DMB.[1]

The DAB standard was initiated as a European research project called Eureka-147 in the 1980s.[2][3] The Norwegian Broadcasting Corporation (NRK) launched the first DAB channel in the world on 1 June 1995 (NRK Klassisk),[4] and the BBC and Swedish Radio (SR) launched their first broadcasts later that year. DAB receivers have been available in many countries since the end of the 1990s. The original version of DAB used the MP2 audio codec. An upgraded version of the system was released in February 2007, called DAB+, which uses the HE-AAC v2 (AAC+) audio codec and is more robust and efficient. DAB is not forward compatible with DAB+, which means that DAB-only receivers are not able to receive DAB+ broadcasts.[5]

DAB is generally more efficient in its use of spectrum than analogue FM radio,[6] and thus can offer more radio services for the same given bandwidth. The broadcaster can select any desired sound quality, from high-fidelity signals for music to low-fidelity signals for talk radio, in which case the sound quality can be noticeably inferior to analog FM. High-fidelity equates to a high bit rate and higher transmission cost. DAB is more robust with regard to noise and multipath fading for mobile listening,[7] although DAB reception quality degrades rapidly when the signal strength falls below a critical threshold (as is normal for digital broadcasts), whereas FM reception quality degrades slowly with the decreasing signal, providing effective coverage over a larger area.

As of 2021, 42 countries are running DAB services.[8] The majority of these services are using the upgraded DAB+, with only the UK, New Zealand, Romania, Brunei Darussalam and the Philippines still using a significant number of (original) DAB services. In many countries, it is expected that existing FM services will switch over to DAB+; so far, Norway is the only country to have implemented an analog switchoff program, having switched its national broadcasters to digital-only in 2017.