Narrator generates lag spikes

We do not have enough information to find the cause of this issue.

Please record a video of this happening and attach it to this report.
If you are on Windows, you can use Windows+Alt+R to open a built-in app for recording game footage.
If you are on Mac (Mojave or later), you can use Shift+Command+5 to open a built-in app for recording your screen.
In case you don't have a program to record videos, we recommend using the free recording software OBS.
In case the resulting video file is too large to be uploaded to the bug tracker directly, please upload it elsewhere (e.g. as unlisted video on YouTube) and link to it here.

_{This issue is being temporarily resolved as Awaiting Response. Once the requested information has been delivered, the report will be reopened automatically.}

Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki

I agree that the bug is not very clear when I describe it with just text. I had some issues with my OBS installation which is why I didn't include a video in the first place.

I noticed that rapidly switching between the narrator options also generates lag spikes. For example, holding down the key sequence that narrator is bound to, which for me (if it can be rebounded) is Ctrl + B. In doing so causes lag. Does that help either of you with explaining the bug?

I discovered this bug when I was working on a mod that uses this narrator to warn the player when he is in danger. It doesn't really help when you are getting a lag spike. I think the problem has something to do with multi threading.

I see. That said, I hope this bug gets fixed soon, though not just because I hate having a lag spike pop up every time I switch the narrator options. What I'm saying is, i wish you good luck with the mod.