Yes, the emoji "button" to the immediate right of the typing field is the one making the noise for me. Unfortunately, as I was describing in another thread, I'm having an issue with emojis in Kii Keyboard. I've been using Kii for years and find it suits my needs better than SwiftKey; however, after transferring it over with the Smart Switch app upon changing phones last week (Kii no longer exists in the Google Play Store), I couldn't get it to recognize any emoji plugin from the Play Store (I previously used Handcent Emoji Plugin with no trouble on my S4), so I had to use an emoji plugin APK to get Kii to recognize it. I've not been able to find a current emoji plugin with up-to-date emojis (taco, middle finger, unicorn, etc.), so I'm stuck with the older version for apps outside of the stock messages where I need to use the emoji feature through Kii (Instagram, Facebook); therefore, using the Kii emoji feature in messages to avoid the clicking sound limits my emoji use. No perfect workaround to be found on my end, but since I usually have my phone on vibrate, I guess the clicking won't be a major issue. (Sorry for the longgg explanation!)