In that case, you'd set the symbol level to none, and to never send the symbol to the synthesizer.

Level 1: None (only those symbols that are deemed highly essential will be reported.
Level 2: Some: Some additional symbols will be reported. All emoji fall in this category. Therefore, to not hear them, set it to none.
Level 3: Most: This is the default for JAWS screen reader, things like dashes, parentheses, brackets, quotes etc. will now be spoken.
Level 4: All: All symbols will be reported. This includes the commas, periods, question marks and exclamation points.
Level 5: Character: These symbols will only be reported when moving by character.