This was the period during which radio broadcasting was introduced and radio receivers went from being like pieces of scientific apparatus to pieces of furniture that would be seen in in many houses in the developed world.
Radios went from battery powered complex devices with multiple controls to mains powered devices with simple controls suitable for the domestic environment.
Growth in the first years was very rapid, tapering off at the end of the decade, slowed by the advent of the Depression. By the end of 1938 the number of licences was 1,102,315, about 16% of the population or 67% of households.
Broadcasting started in Australia at the end of 1923 in Sydney and early 1924 in Melbourne. At the end of 1924 there were nine licensed broadcasters. Over the next five years, the number of licensed listeners grew very rapidly, from over 1,200 licences (0.2 % of population) to over 300,000 (approx. 5 % of population).
The relatively low coverage (approximately 5% of the population) is also somewhat misleading because, at that time, there would normally be only be one radio per household so 5% of the population probably corresponds to about 21% of households. This is based on data from the 1921 and 1933 censuses indicating that the average household size in metropolitan areas was about 4.2 people. The other factor that makes this figure a bit misleading is the fact that until 1930 nearly all of the radio stations were in the capital cities. At the end of 1929 there were 19 licensed stations but only three were in regional cities: Newcastle, Toowoomba and Bathurst.
At the end of this decade, radio was not commonplace but it was not a novelty either. Most people, who did not have a radio, almost certainly aspired to have one.