So much static I can not hear properly

Add and register a handset
Each newly purchased handset must be registered to the telephone base before use. When first purchased, each expansion handset shows NOT REGISTERED.
You may need to charge the phone first.
To register a handset:

·Place the unregistered handset in the telephone base or charger. Press Find for 4 seconds. If the headset screen doesn't light up after the 4 seconds. You will need to charge it some more.
·After making sure it is charged set the telephone on the main base again press and hold the Find button for 4 seconds ( until the red light IN USE comes on) Then release the find button. The headset will show PLEASE WAIT; this takes about 10 seconds to complete the registration. The hand set will show HEADSET REGISTERED and the headset number assigned, you will hear a beep when the registration is finished
·When the registration is complete, the newly registered handset is assigned the next available handset registration number. For instance, if you already have HANDSET 1 and HANDSET 2, the next registered handset is HANDSET 3.
·Makes sure no other headsets are in use at the time or the registration may fail.
·You cannot register a handset if any other system handset is in use. Only one handset can be registered at a time.

Could be a bad hook switch on the phone if you plug a different phone in does it work as it should?

Make sure the Plantronics S11 headset is plugged into your handset jack on your phone, not the headset jack, this will make a difference on most phones. After plugging the S11 into the handset jack on your phone, you will need to pick up your handset receiver and sit it off to the side of the phone to place a call or to receive a call, after you are finished with your call sit the handset receiver back in the cradle on your phone.

Good luck from Headsets Direct!

Unfortunately, the phone does matter. The S12 is designed to work with office style phones where the handset is just the mouthpiece, all other features located on the base. My suggestion is to get a phone of that style (you can find inexpensive ones at Wally world) and connect the headset following the instructions on this link for the Plantronics S12.

Good luck from Headsets Direct!

Make sure the Plantronics S11 is plugged into the handset jack on your phone and not the headset jack. This will make a difference.

Good luck from Headsets Direct!

My guess it's something in the cabling of this device I think it is cheaper to buy a new headset with the same quality. I think that that best solves your problem.

see what TTY mode your phone is in. TTY mode is under call settings or go to voice command and say TTY mode. I keep mine off. This mode is for people who are deaf, and people who are hard of hearing and use hearing aids.

try to check if the mic and the speaker works. or check the configuration properly..

assign the right ip configuration and the connection.

Pm me if problem persists.
I hope this will help you out.. :)
thanks

Try a system reset:
1.  Lift the headset off of the charging cradle, but make sure the headset is turned off.  It will be off if the green light on the front of the base is not lit.  If it's not, push the call answer button once to turn it off.
2.  Push the call answer button and the mute button at the same time and hold them down.  The mute button is the black little wheel at the top of the headset.  Use the tip of your finger to push it straight down and hold it while holding the call answer button.  A green light on the headset will flash for 2 series of flashes.  Wait until the end of the second series then let go of both buttons.
3.  Put the headset back on the charging cradle and wait 30 seconds.  Lift it back up and try to use it.  If this doesn't work, repeat one more time and then disconnect the power from the base and plug it back in.