This started after the Headset Call Controls feature was released with the 4.30 client.
Headset device vendors may deliver features that enable their devices to use a Voice cue or tone to indicate a mute status changes.
If you are hearing an unwanted "Mute on" or "Mute off" message, use the application applicable for your device and adjust your device's settings.
When using the Plantronics (Ploy) 5220 series, the Plantronics Hub is used to manage device settings.
Open the Hub, go to Settings, General. In there you will see a Mute On/Off Alerts setting. Change the setting from Tone and Voice to Tone only and choose Apply. The result should be that you will hear a beep when coming off mute rather than the Voice cue.
View the Amazon Chime User, Administration Guide and API Reference on the AWS Documentation site.
Find more information about the Amazon Chime solution, pricing, customer references, getting started, and other resources.