When we introduced Digital Radio last month, we explained how this completely new technology will commence in Australia in just a few weeks.

The panel below summarises what is required to broadcast high quality audio signals. Analog hifi systems and uncompressed digital systems (eg, compact disc) aim to produce a close replica of the original sound but this uses wide bandwidth and can require high transmission power.

The AAC+ compression process aims to transmit what your ears and brain perceive but employs much reduced bandwidth and transmission power.