A thin disk, especially in a microphone or telephone receiver, that vibrates in response to sound waves to produce electric signals, or that vibrates in response to electric signals to produce sound waves. 膜片,振動板一種薄的圓盤(尤其是在麥克風和電話收話器里那種)響應聲波振動產生信號或者響應電信號振動產生聲波