There is a bug in v4.60 released today that affects users who have custom voice commands, specifically one or more voice commands with partial word matching enabled. You will see an error like TypeError: a.slice is not a function
We have fixed the bug and released a new version v4.61, it is now live. Please restart your Chrome browser to pick up the latest version.
One way to fix in the interim, go to the Voice In Options page, scroll down to Voice Commands section and click on Sync button. That will fix the issue.