Effect of Internet Service Quality on Streaming?

I’ve struggled for a long time with sound getting much, much worse around dinner time, and in some rare cases I don’t get depth, clarity, dynamics and imaging back until around midnight. Like many people I’ve attributed this to noise on my AC lines. But recently I’ve been wondering if maybe internet service quality is at least contributing to the issue in some manner. When I run tests it appears that speed, jitter, and latency are all higher at times when the sound is poor. That got me wondering if anyone knows whether one type of internet service is better than another for HiFi streaming? For example, is ADSL or DSL better, or does it matter? And what about speed? Particularly interested in anyone who has real world experiences from experimenting in this area…