Build Human-Like AI Voice App with Gemini 3.1 Flash TTS

AI voice technology has a serious downside. It really works like a robotic, studying a script phrase by phrase, with no emotions or feelings. It is likely to be intelligent, but it surely issues much less if there isn’t any human feeling connected to it. The best way the AI generates its voice makes it laborious to really feel such as you’re having a considerable dialog.

This all modified with Google DeepMind releasing the Gemini 3.1 Flash TTS on April 15, 2026. This TTS is not only a sophisticated speech synthesizer, but it surely additionally now capabilities as an AI speech director!

This expertise lets you create a voice actor studio with none actual tools, just by utilizing an API name or in Google Studio. Now, allow us to take a look at the brand new options of this expertise, what it means to you, and most significantly, three real-world tasks you might create and use instantly with it!

What Makes Gemini 3.1 Flash TTS Completely different?

In earlier variations of AI TTS, the one choice for you was fundamental voice and pace management. The Gemini 3.1 Flash TTS is a big enhancement over earlier generations and supplies a number of recent options.

The brand new options out there with Gemini 3.1 Flash TTS embrace:

• Audio Tags: Add Pure Language “Stage Instructions” into your transcript. For instance, telling the mannequin to sound like they’re excited, to whisper a secret, or to pause earlier than persevering with will consequence within the mannequin performing as requested.
• Scene Instructions: Outline the Environmental and Narrative context for your complete script, making certain that characters stay in character for a number of successive dialogue items mechanically.
• Character Profiles: Set up distinctive, up-to-date audio profiles for every character. Apply your Director’s Notes to set the supply of every character’s Audio Profile with respect to: Tempo, Tone and Accent.
• Inline Pivot Tags: Audio system can quickly change from Regular to Panicked with out the necessity for a separate API name, even when it’s halfway via a dialogue.
• Exportable Settings: As soon as the voice has been configured, export the precise configuration to the Gemini API code for quick use.

Each audio file created with Gemini 3.1 is embedded with “SynthID”, an invisible audio signature developed by Google DeepMind to assist observe the utilization of artificial audio information. It mainly supplies a technique of detecting artificial audio from historically produced audio information.

Getting Began with Gemini 3.1 Flash TTS

The Gemini 3.1 Flash TTS has three out there accessible platforms at present:

• Developer customers can preview via Gemini’s API and the Google AI Studio
• Enterprise customers can preview via Vertex AI
• Google Vids is offered to Workspace customers solely

For the 2 examples that make the most of API expertise under, please you’ll want to get a free Gemini API Key to make use of by visiting aistudio.google.com. The third instance would require only a internet browser to entry.

App 1: Construct an Emotional Audiobook Narrator utilizing Gemini API

In our real-world check of the Gemini 3.1 Flash TTS, we will construct a Python program for changing plain textual content tales to audiobooks with distinct sounds of emotion utilizing audio tags. That is how audio tags can drastically enhance the standard of the TTS audio within the audiobook course of. Audiobook TTS typically has a monotonous tone; nonetheless, if you management the feelings via the audio tags per scene, there must be a noticeable distinction within the audio output.

Directions:

1. Set up the Gemini Python SDK:

pip set up google-generativeai

2. Create a file named audiobook.py and paste within the following code:

import google.generativeai as genai
import base64
genai.configure(api_key="YOUR_API_KEY")
story = """
[calm, slow, hushed narrator voice]
The outdated home had been empty for thirty years.
[building tension, slight tremor in voice]
As she pushed open the door, the floorboards groaned beneath her.
[sharp, alarmed, fast-paced]
Then she noticed it. A shadow. Shifting towards her.
[relieved exhale, warm and soft]
It was simply the cat. An outdated tabby, blinking up at her at the hours of darkness.
"""
shopper = genai.Shopper()
response = shopper.fashions.generate_content(
    mannequin="gemini-3.1-flash-tts-preview",
    contents=story,
    config={
        "response_modalities": ["AUDIO"],
        "speech_config": {
            "voice_config": {
                "prebuilt_voice_config": {"voice_name": "Kore"}
            }
        }
    }
)
audio_data = response.candidates[0].content material.components[0].inline_data.information
wav_bytes = base64.b64decode(audio_data)
with open("audiobook_output.wav", "wb") as f:
    f.write(wav_bytes)
print("Saved: audiobook_output.wav") 

3. Substitute the placeholder of “YOUR_API_KEY” with your individual API KEY and run this system

python audiobook.py

4. Open and hearken to the audio file positioned at audiobook_output.wav

The stage instructions present in brackets will point out how the narrator ought to emotionally interpret every chapter of an audiobook. For instance, by studying every chapter, the narrator will go from a peaceful whisper to confusion and panic, adopted by a peaceful aid in a single steady audio recording.

Output:

Enhance it additional: Discover any chapter from the Undertaking Gutenberg website and use it within the audiobook; then loop via the paragraph in a chapter. You may as well tag the sentiment for every paragraph utilizing the sentiment audio tags to create your individual audiobooks. By this methodology, it is best to be capable of create an on the spot and expressive audiobook with little or no studio time required.

App 2: Multi-Character Podcast Generator utilizing Gemini API

On this test-case, we’ll use the multi-speaker/host function of Gemini 3.1 Flash Textual content-to-Speech. For this, we’ll construct a podcast script with two voices (two separate speeds, tones, and attitudes) from one single API name inside the similar audio file.

Curiously, there isn’t any want to attach 2 API calls, and there’s no want for post-production for this. Simply present a single immediate that can convert to 2 separate personalities right into a single audio file.

Directions:

1. Create a script known as podcast_gen.py

import google.generativeai as genai
import base64
genai.configure(api_key="YOUR_API_KEY")
transcript = """

Two tech journalists debate whether or not AI voice is overhyped.
Alex is skeptical and speaks rapidly with a dry tone.
Jordan is enthusiastic, heat, and barely sooner when excited.


Yearly somebody declares that is the AI voice breakthrough.
And yearly, the demos sound nice however actual adoption drags.


However this time the numbers again it up. We're not speaking demos —
we're speaking manufacturing deployments delivery precise product.


Deployments of chatbots that also mispronounce "Worcestershire."
Unbelievable milestone.


Okay, truthful. However the trajectory — you genuinely can not argue
with the place that is heading in twelve months.

"""
shopper = genai.Shopper()
response = shopper.fashions.generate_content(
    mannequin="gemini-3.1-flash-tts-preview",
    contents=transcript,
    config={
        "response_modalities": ["AUDIO"],
        "speech_config": {
            "multi_speaker_voice_config": {
                "speaker_voice_configs": [
                    {
                        "speaker": "Alex",
                        "voice_config": {
                            "prebuilt_voice_config": {"voice_name": "Fenrir"}
                        }
                    },
                    {
                        "speaker": "Jordan",
                        "voice_config": {
                            "prebuilt_voice_config": {"voice_name": "Aoede"}
                        }
                    }
                ]
            }
        }
    }
)
audio_data = response.candidates[0].content material.components[0].inline_data.information
wav_bytes = base64.b64decode(audio_data)
with open("podcast.wav", "wb") as f:
    f.write(wav_bytes)
print("Podcast saved: podcast.wav")

2. Execute it by executing the instructions proven under:

python podcast_gen.py

3. Open podcast.wav file and hearken to the 2 distinct voices representing the 2 personalities (the audio recordings may have been created with out using a recording studio).

Output:

Enhance it additional: To develop upon this, level an online scrape instrument at any article you discover in a information supply or Reddit thread, create a 10-line abstract that converts that article right into a two-host debate-style script, and ship this to your podcast_gen.py. Now you should have an automatic “AI Every day Information Podcast” that can run every day out of your crontab.

App 3: Direct a Film Trailer Voice-Over utilizing Google AI Studio

The Banana Cut up & Liberty Bell are collaborating to current you with a shocking film trailer voice-over. You can be doing every thing via the Google AI Studio browser console; subsequently, there isn’t any want for coding or further setup. You’ll really feel utterly artistic on this undertaking, as you develop into the artistic director for this undertaking.

There are three components to this, and they’re as follows:

Prepared the Mannequin

1. Go to aistudio.google.com. As soon as there, log in together with your Google account. You’ll not want a bank card for the free-tier use of the service.

2. Select the Mannequin. As soon as logged in, choose the Gemini-3 TTS Preview. Will probably be titled on the right-hand sidebar beneath “Run Settings.”

Set the Scene

3. Use the textual content under to create a scene within the supplied textbox on the prime of the Google AI Playground, earlier than you choose the masculine or female voice(s):

A darkish film theatre. The display glints. The viewers is holding their breath.

This may give the mannequin a context during which to take care of character for all of the audio system all through the manufacturing.

4. Create your Pattern Context. On this space kind: The narrator has simply accomplished a protracted silence. The bodily rigidity is at an unbelievable stage.

This tells the mannequin what kind of emotional state existed previous to the primary line of dialogue getting used.

Full Speaker Profiles

5. Full Speaker 1 – Zeph’s (Narrator) dialogue. Within the panel, you will notice that Zephyr is designated as Speaker 1, with the descriptors of “Brilliant, Larger pitch.” This means that he’s to be an pressing and charming narrator, excellent for an epic storyteller. Within the Speaker 1 dialogue block, kind the next:

[slow, deep, dramatic] In a world the place silence is taken into account “the regulation”,

[pause, building anxiety] one voice dares to talk.

[suddenly urgent, with intensity] They hunted her throughout the globe, and destroyed every thing they discovered.

[drops the intensity] Disappeared by any means crucial.

Full Speaker 2 – Puck’s (Villain) dialogue. You will note that Puck has beforehand been designated as “Upbeat, Center pitch”; nonetheless, you may overwrite that power with a temper tag. Within the Speaker 2 dialogue block, kind the next:

[cold, slow, with a menacing air] You need to have by no means spoken.

[softly laughing, threat] There is no such thing as a one else coming that can assist you.

Click on on “+ Add Speech Block” so as to add one other narrative closing for Speaker Zephyr’s narrative phase on the finish of this phase, and sort:

[booming, heroic voice] ECHOES. Coming quickly. Solely in theatres.

Output:

Benchmarks: How Does It Truly Stack Up?

At this level, we are able to see a completely totally different aspect to the story. Whereas Google doesn’t say they’re higher than everybody else, they did submit their Gemini 3.1 Flash TTS (Textual content to Speech) to probably the most thorough unbiased benchmark TTS ever created.

The Synthetic Evaluation TTS Area runs hundreds of nameless blind human choice exams on artificial speech. In these exams, individuals hear to 2 TTS voices and choose the one they imagine sounds probably the most pure, with out figuring out which mannequin produced which voice. There is no such thing as a cherry-picking of samples or scores made by the corporate itself. That is the last word demonstration of how many individuals will desire utilizing every voice within the market. Listed below are among the outcomes of the Gemini 3.1 Flash TTS robotic:

• 1,211 Elo Rating at launch – the very best Elo rating for all publicly out there TTS engines
• “Most Engaging Change” placement – the one TTS within the historical past of TTS with each excessive naturalness and low price per character
• 70+ languages examined – all maintained natural-sounding type, pacing, and accent management
• Produced three or extra totally different audio system in a single coherent output — not produced from concatenated clips
• watermarked with SynthID within the output of every voice; no different mannequin on the leaderboard watermarks with SynthID.

Gemini 3.1 Flash TTS Comparability with Opponents

Most high-quality TTS engines usually are not inexpensive. Most low-cost TTSes sound like TTSes that price an excessive amount of. Gemini 3.1 Flash TTS is the primary TTS to confidently place itself between these fashions. Right here’s the way it stacks up towards the main AI TTS fashions throughout standards that matter:

Conclusion

AI voice expertise has been round for a very long time, and it has been “adequate” for a lot of makes use of. Nonetheless, AI voices weren’t “adequate” for utilization in contexts that require a human voice to painting emotion, or to supply the person any type of artistic management.

Gemini 3.1 Flash TTS modifications all of that. The wealthy set of options makes it the very first AI-based speech mannequin that may really compete with a recorded human voice, particularly to be used in artistic purposes.

The three tasks above are simply your entry level. Assume interactive fiction with branching voiced narratives, multilingual customer support brokers with regional accents, and even AI tutors that sound like they care. With Gemini 3.1 Flash TTS, the sky is the restrict.