You can use mtr, but here’s the rub:
There are hops along your route that do not prioritize ICMP traffic, so you have to keep that in mind when reading the results. Basically what MTR is going to tell you is if there is a hop causing issues that are cascading throughout the rest of the route. If there is a hop that regularly reports back with high ping but the following hops do not, that does not indicate an issue with that hop or your route.
For example, the below MTR shows one hop with very high ping times, but it doesn’t cascade through the rest of the route so there is no issue with that.
HOST: Andrews-MBP-6 Loss% Snt Last Avg Best Wrst StDev
1.|-- router.asus.com 0.0% 10 1.1 1.4 1.0 2.2 0.0
2.|-- X.X.X.X 0.0% 10 1.9 1.9 1.7 2.2 0.0
3.|-- X.X.X.X 0.0% 10 12.6 11.7 3.4 47.4 13.3
4.|-- X.X.X.X 70.0% 10 10876 10832 10785 10876 45.1
5.|-- X.X.X.X 0.0% 10 10.0 11.4 8.1 13.7 1.8
6.|-- X.X.X.X 0.0% 10 14.3 12.9 8.8 20.5 3.4
7.|-- X.X.X.X 0.0% 10 7.5 7.3 7.1 7.7 0.0
8.|-- X.X.X.X 0.0% 10 7.5 7.1 6.7 7.5 0.0
9.|-- X.X.X.X 0.0% 10 7.7 8.4 7.6 12.1 1.2
10.|-- X.X.X.X 0.0% 10 7.3 7.5 7.2 8.6 0.3
11.|-- X.X.X.X 0.0% 10 8.0 8.1 7.7 8.6 0.0
12.|-- X.X.X.X 0.0% 10 36.2 49.0 35.6 128.4 29.6
13.|-- X.X.X.X 0.0% 10 51.9 52.3 51.8 53.8 0.5
14.|-- X.X.X.X 0.0% 10 51.4 51.5 51.2 52.3 0.0
15.|-- X.X.X.X 0.0% 10 52.0 55.7 51.8 86.7 10.9
16.|-- X.X.X.X 0.0% 10 51.8 52.0 51.7 52.8 0.0
17.|-- X.X.X.X 0.0% 10 51.5 51.9 51.5 52.3 0.0
Based on my experience, if you are experiencing issues with poor call quality (assuming) it is likely an issue with the local ISP and MTRs should help you to provide info to them that proves it.