Phone Voice Quality Metrics

Where are all the metrics? We replaced the cordless phone in our kitchen recently. The last phone was some brand I did not recognize that I bought at the local supermarket. It works reliably, but the voice quality is poor. We had an AT&T phone a while back, and it was great, but it died eventually. We replaced it with a Uniden, which was pretty good. When it died, we tried an AT&T phone from Office Depot. I was thrilled to find an AT&T phone, I thought this will be great. But that was not to be. It had some kind of horrible problem and we ended up exchanging it for another Uniden phone, which seems to work pretty well. I would like to see a metric for voice quality, but I haven't.