1. An apparatus to compress a wide-band speech signal, the apparatus comprising: a narrow-band speech compressor to compress a low-band speech signal of the wide-band speech signal and output the compressed low-band speech signal as a low-band speech packet; and a high-band speech compressor to compress a high-band speech signal of the wide-band speech signal using energy information of the low-band speech signal provided from the narrow-band speech compressor, and output the compressed high-band speech signal as a high-band speech packet.