             commentHistory.append(comment)
             commentHistoryIndex = commentHistory.count
         }
+    }
+
+    private func logComment(_ comment: String) {
+        logSystemMessageToTable("comment: [\(comment)]")
+        logSystemMessageToTable("comment.clean: [\(comment.stringByRemovingControlCharacters)]")
+        logSystemMessageToTable("hasControlCharacters: [\(comment.hasControlCharacters)]")
+        logSystemMessageToTable("hasX1c: [\(comment.hasRegexp(pattern: "\\x1c"))]")
+
+        log.debug("[\(comment)] -> [\(comment.stringByRemovingControlCharacters)]")
     }
 
     @IBAction func speakButtonStateChanged(_ sender: Any) {

private extension NSButton {
    var isOn: Bool { self.state == .on }
}
// swiftlint:enable file_length


    @IBAction func comment(_ sender: AnyObject) {
        let comment = commentTextField.stringValue
        logComment(comment)

        if comment.isEmpty {
            scrollView.scrollToBottom()
