An apparatus and method for transmitting a plurality of audio objects using a multichannel encoder and a multichannel decoder are provided. The audio object encoder includes a multichannel encoder determination unit to determine a multichannel encoder to be used for encoding of a plurality of audio objects according to the number of the audio objects, an encoding unit to generate an encoded signal by encoding the plurality of audio objects using the determined multichannel encoder, and a multichannel audio object signal generation unit to generating a multichannel audio object signal, by multiplexing sound image localization information of the plurality of audio objects along with the encoded signal.