Hello plumbing pro's. I hope you can help me pinpoint a couple potential problems. 1. This started a couple weeks ago. When you flush the toilet in the master bath you can hear a gurgling coming from the tub as if air is escaping. Bathroom is set up with 2 vanitys and toilet on left and separate shower and then garden tub on right. Been here 5 years and never heard this noise before. 2. Sprinkler with timer connected to house. Timer stops but water pressure continues through hose to sprinkler. When this occurs you can hear a whine all throughout the house when other water sources are used, Sink, toilet, shower. I was thinking it was caused by some sort of back pressure issue? And possibly related to the smaller whine you hear when washer is running and you flush a toilet? Thanks in advance.