Keyless entry problem on my 2000 Lexus Es300.?

I have the keyless entry on my car, everytime that I could lock or unlock the car it could make a beeping sound, sort of an announcement that car was just locked or unlocked. But now I hit the button on my key to lock it and unlock it and it still locks and unlocks but it just does not make the beeping acknowledgement sound. What may be the problem? thanks in advance.

Maybe the beeper's speaker is broken. If it bothers you, then take it in to a Lexus or Toyota dealership.

ck for a handle under the left side dash turn it