I have not had any work done on the house or anything that might have contributed to some change in the plumbing. I also have a septic tank that was cleaned out about 6 months ago

Hi Sue...

Howling/whining sounds at a toilet usually mean that sediment has gotten stuck under the fill valve washer. Here, the fill valve would need to be disassembled and the washers cleaned or replaced.

Is this something you plan to tackle yourself? Pretty easy job, most of the time.

Let me know...

Mark