MSP430FR60471: Using Analog Filter at the CH0IN and CH1IN

Hi,

we are using MSP430FR6047 for Ultrasonic Sensing and borrowed the circuitry from MSP430FR6047EVM. To reduce noise further, we want to tweak the CH0IN and CH1IN circuitry, which is currently looks like this:

at J5 and J1, two transducers are connected.

I have few questions here:

1. What is the state of CH0OUT or CH1OUT when transducer signal is being acquired? (Is it kept at ground or high impedance)

2. Does it do impedance matching? How does this circuitry helps in the same?

Regards,

Kamlesh