What does Muted Speaker look like on HTC?

On HTC it is the design shipped in Sense 8, shown above at full size. Older revisions are listed beneath it.

When did HTC add Muted Speaker?

HTC first drew Muted Speaker in Sense 7, released March 30, 2015.

HTC Corporation has shipped 2 versions of Muted Speaker. Each is dated, so you can see when the design changed.

HTC

HTC Corporation has drawn Muted Speaker 2 times. Every revision HTC has shipped is below, newest first.

What does Muted Speaker look like on HTC?: On HTC it is the design shipped in Sense 8, shown above at full size. Older revisions are listed beneath it.
When did HTC add Muted Speaker?: HTC first drew Muted Speaker in Sense 7, released March 30, 2015.
How many times has HTC redrawn Muted Speaker?: HTC Corporation has shipped 2 versions of Muted Speaker. Each is dated, so you can see when the design changed.

HTC artwork for this emoji spans 2015 to 2016.