Why do I not can audio on any channel,only static?

My Sennheiser RS120 Wireless Headphones have great for 2 years. Suddenly nothing but static on any of the 3 available channels.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0