Sorry for the delay in responding the model number threw me, for future reference its 40BV705B
Please see attached diagram showing you the inputs available on your TV here, as you will see the TV does not have a mic input, but it does have two sets of audio inputs (one set located on the side for AV, the other on the rear for DVI\PC), however if wishing to use a mic you will need to use an amp, but otherwise you can use the audio inputs as the same as you would a audio Aux or Line In input.
The mic will also only function when the channel is set to DVI\PC or AV.
Please let me know if you need anything clarified.
I havent heard back from you in the last day or so, and just wanted to check if you still require assistance, I would appreciate it if you could rate the service received.