Tricks I've used over thee years ..

Reload in new instance of browser (close browser and re-open it)
Clear browsing history for the last 24 hours (sometimes helps to clear cached local content)
FlushDNS (command line) .. makes your system relocate the path to the site by looking for the path fresh instead of using a cache

Use TraceRT in a command line .. shows if there is simply some device between you and the site causing the delay, which is kind of like knowing there is an accident on a given highway and things are backed up and getting rerouted.

/It is after all an information highway and maybe you are getting detoured through Chicago instead of Toronto/Montreal (for example) because some device has failed

It is actually pretty amazing how efficient the internet is at handling problems like this, but it does occur where a single device failing affects one location and not another (or more than another) on a given path ..

Really hard to say without access to said machine

I do not work here, but the benefits are still awesome
Make your sound your own!