Patent US 9,608,744

A receiver can extract digital data from wireless radio frequency signal. The digital data contains index data and corresponding content digital audio data. The index data can comprise compressed digital audio data. The index data and content digital audio data are stored in memory. The index data can be retrieved from the memory, decompressed and then converted to analog audio signals. A user can use the analog audio signals from the index data to select audio content for playing by the receiver.