after macos 10.15.4 update, voice control extremely slow

It is not possible to roll back to 10.15.3 now that 10.15.4 is out. You can file your comments at Feedback - Apple Support. There is little you can do. Part of the problem is that VC dictation and commands require data movement between your computer and Apple servers. Part of the problem is the changes made with VC and Dictation after Mojave. If these services are critical for you, then consider downgrading to Mojave, if your computer model is supported. How to Downgrade from macOS Catalina to Mojave. I don't know if the 2019 MBA can run Mojave.

Having the exact same problem, I thought it was me. And yes internet connection is normally working. Yes 100% the new update did something to VC which is terrible since I use it on a daily basis for work. My only saving grace is that the VC on my iPad is functional and although a little bit of a pain its still easier than tying everything out until apple can fix it.

Sorry this isn't a helpful fix but I'm glad I'm not alone in having this issue

Voice control was introduced before Catalina but not as a standalone element. It was part of the Extended Dictation Support in Dictation.

Since you are so well-versed as to know my answer was unacceptable, then perhaps you can answer your question yourself. Of course, if you could, then you wouldn't be here.

I am also having this problem. Voice Control is completely unusable for me after updating to MacOS 10.15.4 yesterday. Some commands work after a minute or two, but it is pointless to use, especially for dictation. I also noticed that it is using a much higher percentage of the CPU than normal. Something definitely got messed up in the latest update. And no, my Internet is not the issue unless a 1Gb down/45Mb up connection, which I just did a speed test to verify, is insufficient.

Downgrading is not a solution as even Advanced Dictation was very limited in Mojave. As someone with a disability that affects muscle strength, I have come to heavily rely on the extended VC capabilities in Catalina.

I have this problem as well. I have not used my laptop since I was on Spring Break, and then I updated it and classes resumed, and I tried to use Voice Control to type my notes which I read from textbook into Microsoft Word and my Voice Control is delayed by 30 seconds for 6 words. For example, it takes 30 seconds for Voice Control to type into Word, "the dog ran across the street." Which is pointless use and I don't read like this. I usually read 100pgs aloud and I Voice Control (compact it) it into 17 pages. Although, I figured out Word has it's own dictation I hope it proves to be better than Apples Voice Control. I tried uninstalling Catalina but that took forever, and it didn't show that I had a backup. Wow, I see why Apple is loosing their customers. So annoyed. I also spoke to customer service for a whole 1 hour and all she did was tell me to reset PRAM and to boot in Safe Mode, and to reinstall Catalina again. To no avail my Voice Control is dead. Such a shame, the IT must have quit and created this issue. Get it together Apple.

I have the same problem. Since Nuance discontinued it's support for Dragon for the Mac, I upgraded from macOS HIGH Sierra macos Catalina on my mid 2015 MacBook Pro excitedly anticipating the superiority of an Apple product. What a disappointment. With Catalina 15.3 it was sluggish and barely usable. But after mistakenly upgrading to Catalina 15.4 it was so slow that it became totally unusable. I thought the problem may have been the age of my computer. So I bought the new 16 inch MacBook Pro with 32 gigabytes of RAM. There was some improvement but only as good as my old MacBook Pro running Catalina 15.3. I think an important feature of the problem that may be helpful to Apple in creating a solution is that Voice Control slows progressively with use. A computer restart increases the Voice Control responsiveness which then again progressively slows overtime. Additionally, use of the Number overlay and grid overlay seem to be the features most responsible for the slowdown. I hope Apple recognizes this problem and that more members of the disabled community, like myself, Will speak up to push Apple to fix this and other idiosyncrasies that exist in Voice Control which will allow us lead more productive lives like Dragon once did.

OK, just going to say up front, sorry, I don’t have any helpful responses to solve this. But I’m so glad I found other people with this problem! For months I thought I was the only one.

I was fortunate enough to have an old 10.15 back up in my Time Machine that I reverted to, which wasn’t a perfect solution since it was outdated, but at least it taught me to always take a back up before updating.

Again, no solution to offer here, but in the interest of finding others who use voice control, I created a sub Reddit for people to share tips and tricks on. Hopefully we can get a more thriving community for VC related stuff!

https://www.reddit.com/r/VoiceControl/

I have the same problems, and more. Is Apple serious about Voice Control?

I also installed that update but it had no effect on voice control. Would you give me more information about your hardware? It may make a difference. Thank you

Unacceptable and poor improvement is periodically restarting the computer which speeds things up oh.