Google prepares voice customization for Gemini with speed, energy, formality, and warmth controls

Google is preparing to let users customize Gemini's voice output across four parameters: speed, energy, formality, and warmth, according to code discovered in the Google app 17.41.12 beta.

The controls

The feature will offer slider-based adjustments:

• Energy, Formality, and Warmth: Low, medium, and high settings
• Speed: Slow, normal, and fast options

According to strings in the app code, these customizations will apply to both Gemini Live conversations and standard text chat responses where voice output is used.

Context and timing

Google has not officially announced this capability. The company did state at I/O that regional dialects were coming to Gemini, but did not mention granular voice customization controls.

The timing follows Apple's introduction of similar features in iOS 27, which lets users adjust Siri's pace and expressivity. Apple's implementation extends across Maps and Safari as well.

Google released two new Gemini voice options shortly after I/O 2026, suggesting the company has been actively working on voice personalization.

Implementation details

The discovered code includes specific labels for each control:

• assistant_robin_mc_voice_selection_customize_header
• assistant_robin_mc_voice_selection_energy_label
• assistant_robin_mc_voice_selection_formality_label
• assistant_robin_mc_voice_selection_speed_label
• assistant_robin_mc_voice_selection_warmth_label

The "robin_mc" reference in the code suggests these controls are part of Gemini's voice system architecture.

What this means

Voice customization represents a shift toward more personalized AI assistant interactions beyond simple voice selection. By offering control over characteristics like formality and energy, Google is acknowledging that users have different preferences for how AI should communicate—professional users may prefer formal, measured responses while casual users might want warmer, more energetic delivery.

The feature remains unannounced and could be modified or not ship at all, as is common with capabilities found in beta code. However, the specificity of the implementation and its alignment with industry trends suggest Google is seriously pursuing this functionality.