Siri stops mid sentence

I had that same issue over here as well and it seemed like it stopped after a while. I believe I just rebooted my phone, turned off Siri completely and turned it back on.

It sounds like it may be an issue at Apple's end. I did report it, as well as the issue I've been having when asking siri to shut off my wi-fi, it'll respond that my wi-fi is now off, but when checking it again, it's still on. Now I just make it a habit to ask her a few times until she responds that wi-fi is already off, then I know it's truly off.

Again, brought this to Apple's attention and from what I've heard from a friend who's on the developer beta, they mentioned that Apple is aware of this and is working on it.

I'm having exactly the same issue! This issue is really annoying, as Siri would just stop midway through her response.

I thought I was just crazy over here, or something. I'm having exactly the same issue. If you wait a few seconds, it will usually come back speaking again, but whatever was said in the time it went silent, you've now missed. I tell ya, the Siri voices on the mac, the issue here with Siri on iOS, I'm at a point where I think Apple needs to just reconsider if Siri is worth it!

Hi, Please send the report to apple accessibility. you can reach them at: accessibility@apple.com

Hi. I’m running the new software on my 2020 SE. I recently updated to the 14.01 version which came out about two weeks ago and that very same issue happened to me via Siri would stop after about two words. It merely happened when I done a search by holding down the button and asked to search the web for webpages. It would just start and then I will cut out. I went into Siri. Turned it off and turn it on again and that seem to have fixed the issue for me also rebooted my phone I think two times. But as I say I went into Siri turned off Siri did not change the language just turned it off and back on again and that seem to have fixed the issue with me as I had it for about one day

This was happening to my sighted wife when she was using Siri to get directions to a location while driving. Siri would start to speak the upcoming direction (e.g., In 1 mile, take the exit...) but stop after the first few words and before the actual location was mentioned. It made using Siri for directions very frustrating. Also, it didn't happen every time and seemed to happen mostly with the advanced directions, but the immediate instruction was usually spoken completely. This was using an iPhone 11 Pro Max and iOS 14.5.1.

Go to Siri settings, disable Listen for “Hey Siri”, reboot your iPhone then re-enable Listen for “Hey Siri”. It should solve your problem.

I'm having the same issue here... Some times when I even ask Siri to call someone, the phone starts calling that person without Siri saying, "calling X Y Z". Really weird.
By the way, I was just using X Y Z as an example. :-)