I thought this might fit here as anywhere.
Both of us are getting on, and although my wife's hearing is better than mine by a deal, it isn't as good as a 20 y.o. I wear two aids and ATM am hampered by residual effects of sinus problems.
Whether phone or me, I had to phone my wife from home as she was sitting our grandchildren. First time I could not hear anything: she told me later she was shouting. Within minutes a second call gave no problem.
Using Quiet Line I hear no noise, wife thinks she hears some but is unsure, but son-in-law says there is noise.
Now noise margins lay atop a variable base, but is there any way to measure and record the actual
noise levels?