A coding apparatus includes a generation unit configured to generate first coding information used for first coding of a first audio signal and second coding information used for second coding of a second audio signal, and generate third coding information used for the first coding of the second audio signal and fourth coding information used for the second coding of a third audio signal; a first coding unit configured to generate first data and second data; a second coding unit configured to generate third data and fourth data by performing the second coding on the third audio signal; and a multiplexing unit configured to generate a stream of the first audio signal and a stream of the second audio signal. The third data is decoded in place of the second data in a case where a loss or an error has occurred in the stream of the second audio signal.