PORTABLE ELECTRONIC APPARATUS

PROBLEM TO BE SOLVED: To prevent a sound wave from a speaker from being canceled, even if pronunciation of a speaker induces vibration of a battery lid, and a sound wave of opposite phase is generated from the speaker, in a cellular phone including a speaker.SOLUTION: A piezoelectric element 13 is provided on the inner surface of a battery lid 5. When pronunciation of a speaker 10 induces vibration of the battery lid 5, and a sound wave of opposite phase from that of the speaker 10 is generated, the piezoelectric element 13 is vibrated in the inverse mode of vibration of the battery lid 5. Consequently, vibration of the battery lid 5 is suppressed, and the sound wave from the speaker 10 is not canceled.