How to Write Text That Sounds Great When Spoken by AI

Why Text Matters for AI‑Generated Speech

When you’re building a voice‑enabled product, you might think that the magic happens only in the neural network that turns raw audio into a human‑like voice. In reality, the source text is just as crucial. A poorly written sentence can make even the most advanced TTS system sound robotic, stilted, or, worst of all, unintelligible. This article dives into the practical tricks that will make your text sound great when spoken by AI, with a focus on voice‑cloning and text‑to‑speech workflows. We’ll also show you how to hook everything up with ElevenLabs, the leading platform for realistic voice synthesis.

1. Keep Sentences Short and Simple

The 8‑Word Rule

A general rule of thumb for TTS is to keep sentences to 8–12 words. Long, complex sentences create pauses that feel unnatural. If you need to convey a lot of information, break it into multiple shorter statements.

Bad: “Despite the fact that we have been working on the new feature for several months, the final release date will be pushed back due to unforeseen technical challenges.”
Good: “We’ve worked on the new feature for months. The release date is delayed because of technical challenges.”

Use Contractions

Contractions (e.g., “don’t,” “it’s,” “they’re”) make the speech feel more conversational and reduce the need for the TTS engine to pronounce the extra syllables. Most TTS engines handle contractions naturally, but it’s a quick win you can’t ignore.

2. Punctuation Is Your Friend

TTS engines rely on punctuation to determine pauses, intonation, and emphasis. Missing commas or periods can cause the model to read a string of words in a flat tone.

Punctuation	Effect on Speech
Period (.)	Full pause, end of thought
Comma (,)	Short pause, keeps flow
Exclamation mark (!)	Raised intonation, emphasis
Question mark (?)	Lowered intonation, question tone
Ellipsis (…)	Slight pause, trailing off

Tip: If you’re writing dialogue or instructions, double‑check that each sentence ends with the proper punctuation.

3. Use Prosody Tags for Fine‑Tuning

Some TTS APIs, including ElevenLabs, support prosody tags—small XML/HTML snippets that let you control pitch, speed, and volume for specific words or phrases. This is especially handy for brand voices or when you want to emphasize a call‑to‑action.

<prosody rate="slow" pitch="high">Attention: This feature is now available.</prosody>

Python Example with ElevenLabs

import requests

API_KEY = "YOUR_ELEVENLABS_API_KEY"
HEADERS = {"xi-api-key": API_KEY, "Content-Type": "application/json"}

payload = {
    "text": "Welcome to your new dashboard. <prosody rate=\"slow\" pitch=\"high\">Get started now!</prosody>",
    "voice_settings": {
        "stability": 0.75,
        "similarity_boost": 0.85
    }
}

response = requests.post(
    "https://api.elevenlabs.io/v1/text-to-speech/your_voice_id",
    json=payload,
    headers=HEADERS
)

with open("output.wav", "wb") as f:
    f.write(response.content)

Note: Replace your_voice_id with the ID of the voice you’ve cloned or chosen. The stability and similarity_boost parameters are optional but can help smooth out the audio.

4. Avoid Jargon and Ambiguity

If the audience isn’t familiar with industry terms, the AI might pronounce them oddly or insert unnecessary pauses. Stick to plain language or provide a brief explanation before using specialized vocabulary.

Bad: “Utilize the API’s CRUD endpoints for data manipulation.”
Good: “Use the API’s Create, Read, Update, and Delete endpoints to manage your data.”

5. Test with Real Users

Even the most carefully crafted text can sound off in the wild. Run a quick A/B test with a handful of real users to see which version feels more natural. You can use a simple survey or ask for qualitative feedback.

# Using curl to fetch an audio file from ElevenLabs
curl -X POST "https://api.elevenlabs.io/v1/text-to-speech/your_voice_id" \
     -H "xi-api-key: YOUR_ELEVENLABS_API_KEY" \
     -H "Content-Type: application/json" \
     -d '{"text":"Hello, world!"}' \
     --output hello.wav

Play the hello.wav on multiple devices (phone, laptop, headphones) to catch any artifacts that might be device‑specific.

6. Leverage Voice Cloning for Brand Consistency

Voice cloning lets you create a synthetic voice that sounds like a real person—often a brand spokesperson or a beloved character. The process generally involves:

1. Collecting Audio Samples: 5–10 minutes of clean, high‑quality speech.
2. Transcribing the Audio: Accurate transcripts are essential for training.
3. Uploading to the Platform: Most services (ElevenLabs included) offer a straightforward UI or API.
4. Fine‑Tuning Parameters: Adjust pitch, speed, and timbre to match your brand personality.

Quick Clone with ElevenLabs

import requests

API_KEY = "YOUR_ELEVENLABS_API_KEY"
HEADERS = {"xi-api-key": API_KEY, "Content-Type": "application/json"}

# Step 1: Create a new voice
create_voice = {
    "name": "Brand Voice",
    "description": "Voice for our brand assistant",
    "sample_rate_hertz": 22050,
    "language_codes": ["en-US"],
}
response = requests.post(
    "https://api.elevenlabs.io/v1/voices",
    headers=HEADERS,
    json=create_voice
)
voice_id = response.json()["voice_id"]

# Step 2: Upload audio samples
with open("sample1.wav", "rb") as f:
    files = {"file": f}
    response = requests.post(
        f"https://api.elevenlabs.io/v1/voices/{voice_id}/audio",
        headers={"xi-api-key": API_KEY},
        files=files
    )

print(f"Voice {voice_id} created and sample uploaded.")

Once your voice is trained, you can reuse it across all your TTS requests, ensuring a consistent auditory brand experience.

7. Respect Ethical Boundaries

Voice cloning can be powerful, but it also raises ethical concerns. Always:

• Get Consent: Ensure you have permission from the speaker whose voice you’re cloning.
• Avoid Misuse: Don’t clone voices for malicious or deceptive purposes.
• Label Synthetic Speech: Transparency builds trust with your audience.

8. Integrate Seamlessly into Your Workflow

If you’re already using a CI/CD pipeline, add a step to generate or update TTS assets automatically. For example, you can:

• Store text files in a Git repo.
• Run a script that pulls the latest text and pushes the audio to a CDN.
• Use webhooks to trigger updates on your front‑end whenever the audio changes.

# Example script: generate_audio.sh
TEXT_FILE="content.txt"
OUTPUT_WAV="content.wav"

curl -X POST "https://api.elevenlabs.io/v1/text-to-speech/your_voice_id" \
     -H "xi-api-key: $API_KEY" \
     -H "Content-Type: application/json" \
     -d "{\"text\":\"$(cat $TEXT_FILE)\"}" \
     --output $OUTPUT_WAV

9. Keep an Eye on Updates

AI voices evolve rapidly. Platforms like ElevenLabs frequently roll out new features—better prosody controls, higher fidelity models, or new voice‑cloning techniques. Subscribe to their newsletters or follow their GitHub to stay ahead.

Call to Action

Ready to make your text sound as natural as a human conversation? Dive into ElevenLabs and start cloning voices, fine‑tuning prosody, and delivering flawless AI‑generated speech today.

Try ElevenLabs now: https://try.elevenlabs.io/kr07zfuqn1bp

Happy coding—and happy speaking!