AI vs Human Voices: When and Why to Use Synthetic Voices

Synthetic voices have emerged as an efficient, cost-effective alternative to traditional voice production, opening the door to premium audio creative for brands of all sizes. Despite the headlines, advertisers don’t have to choose between “team human” or “team AI” to run campaigns that strike the right chord. The smartest strategy—and the future of the advertising industry—lies in leveraging both human and AI voices to maximize ad efficiency and impact.

Explore the differences between synthetic and traditional voice ads, when to pick one over the other, and the best practices. 

What are synthetic voice ads?

Synthetic voice ads are audio placements created using AI and text-to-speech (TTS) technology to convert written text into spoken audio. This technology has advanced rapidly in recent years, shifting from stilted, robotic tones to sounds nearly indistinguishable from human speech.

These ads work for both streaming audio and podcasts, allowing advertisers to create, customize, and retake audio creatives without delays. Thanks to synthetic voice ads, brands can create high-quality audio ads without booking a studio, hiring voice talent, or navigating a lengthy production process.

AudioGo, our in-house, self-serve platform, enables you to select from a variety of artificial (but realistic) voices instantly—no need to set up casting calls or navigate potential schedule conflicts. AudioGo offers 14 voice types in English and three voice types in Spanish, whether you’re looking for an informative, familiar, friendly, or youthful tone. This solution allows any brand to easily enter the audio advertising space, regardless of your budget or team size.

What’s the difference between traditional and synthetic voice ads?

Quality

If you’re worried about the authenticity and quality of synthetic voices, you’ll be pleased to know that the gap is narrowing quickly. AI-generated voices are now almost indistinguishable from human ones. In a past study, only 42% of participants correctly identified generic AI voices in short sentences, while 47% got it right for full ads. 1

Production

When deciding between traditional voice and synthetic voice ads, a key difference for advertisers lies in the production workflow. Traditional ads follow a linear path: script approval, casting, recording, editing, and final mixing. If you catch an error or decide to change a promotional offer after the recording session, you’re looking at a re-recording fee, additional editing, and potential delays in your campaign launch.

By contrast, AudioGo Synthetic Voice is a dynamic self-service solution, allowing for unlimited retakes and script rewrites without any delays. This real-time flexibility offers greater creative control and removes the fear of “locking in” mistakes—you can simply generate a new ad version while staying on schedule. 

Performance

Once your ad is out in the wild, performance is critical. A study found that ads with synthetic voices matched traditional voice ads when it came to brand engagement and purchase intent. 1 While the study’s participants may have rated human voices as more relatable or emotional, their neurological engagement levels were almost identical when consuming synthetic voices. 

What are the benefits of using synthetic ads over traditional voice ads?

Both ad types have their unique strengths. Here are several situations when synthetic voices are the clear winner. 

Ad personalization at scale

Synthetic voice ads offer a tactical advantage for brands that need to move fast and optimize often. With AdsWizz’s Dynamic Creatives with Synthetic Voice, you can create millions of hyper-personalized ad variations based on one’s location, real-time weather conditions, demographics, and more. 

Accelerated production 

If speed is paramount to your campaign, opt for synthetic voice ads. Recording multiple versions of a traditional voice ad requires production effort and consumes plenty of time. The turnaround time from concept to live ad can take weeks (if not longer), which can be too late if you’re looking to capitalize on a cultural trend or viral moment. Meanwhile, AudioGo Synthetic Voice allows advertisers to generate audio creatives in seconds. However, it’s important to note that a quicker production turnaround can depend on your brand’s learning curve when using AI. If it’s your brand’s first time using synthetic voices, you might expect to spend more time re-generating and editing AI voices compared to using traditional voices. 

Real-time revisions 

The ability to iterate is crucial for ad optimization. With AudioGo Synthetic Voice, advertisers can do unlimited retakes and make on-the-go updates to the script, voice, or style. Changed your mind on the type of synthetic voice you want? Swap it without causing any delays. Looking to tweak the promotional offer you’re advertising? Your ad copy can be updated and re-generated quickly. 

Brand consistency 

Finding a traditional voice actor who perfectly embodies your brand is a win, but ensuring their availability for every subsequent campaign over the years can be challenging. Instead, synthetic voices offer a high level of consistency. Once a synthetic voice is selected, it’s available on-demand, ensuring every touchpoint and creative asset maintains a cohesive sound. 

Cost-effectiveness

No more studio rentals, talent fees, and recording engineer costs. AudioGo Synthetic Voice is free of charge, making it ideal if you’re a small business or working with a limited budget. With this in mind, brands can produce professional-quality ads and reallocate savings directly to media spend to reach a wider audience.

What are the benefits of using traditional voice ads over synthetic ads? 

While synthetic voices offer speed and scale, traditional voice ads may be a better fit for campaigns that rely heavily on storytelling or emotion. In these cases, the human element isn’t just a preference but a performance necessity.

Emotional storytelling and nuanced delivery

Comedy relies on timing, subtle pauses, or sarcasm—elements that even the most advanced AI may not be able to master. “Reading” a joke is different from “telling” one, and you may need a human actor to effectively land a punchline. 

Premium host-read ads

A powerful ad type is the host-read ad, where the host of a podcast delivers the message themselves. Host-read ads leverage the unique relationship listeners have with their favorite personalities, capitalizing on trust and high engagement. When a popular host like Conan O'Brien or Alex Cooper reads your ad, this carries a level of credibility and intimacy that AI cannot match.

The best practices for adopting synthetic voices

While synthetic voice technology is powerful and constantly innovating, it requires a strategic approach. Here’s how to get the most out of your synthetic voice creative.

Create a framework for transparency 

Despite the creative advantages of using synthetic voices, biases towards AI still exist across all demographics. Listener perception is influenced by your ad disclosing the usage of AI—either reinforcing customer trust or raising authenticity concerns. More and more states are passing AI disclosure laws, and while regulation currently doesn’t exist when it comes to audio ads, this could change in the future.  To modernize your strategy, develop an AI framework, and answer these questions: How will AI be used in your creative workflow? How do disclosure practices align with your brand? How can you monitor evolving regulations? 

Ensure clarity and consistency 

Precision is one of the advantages of synthetic voices, but it requires the human touch to deliver a flawless output. If you’re working with multiple synthetic voice types, guide them to ensure consistency in pronunciation to avoid misinterpretations and enhance audibility. If your script includes acronyms or specific terms, help your synthetic voices understand the context. 

Emphasize natural sounds 

Not all modern synthetic voices sound robotic, and you can enhance them by aiming for human-like voice inflections. When writing scripts for a synthetic voice, use punctuation strategically. Depending on the platform you use, quotation marks, capitalization, commas, and ellipses serve as stage directions, signaling pauses or changes in intonation and mimicking natural speech patterns.

Take a hybrid approach

Can’t decide between traditional and synthetic voices? Adopt a hybrid approach. You might work with a traditional voice actor to help build your brand—like recording a humorous campaign that’s designed to create an emotional connection with your listener. In the same campaign, you can leverage synthetic voices on AudioGo for short-term conversions. This hybrid approach allows you to bring together the best of both worlds, combining emotional storytelling with timely production. 

The future of audio is human and AI

Synthetic voices expand the toolkit available to advertisers. For small businesses, this innovation removes the financial and production barriers associated with traditional audio ad production. For brands of all sizes, they provide the agility to test and scale like never before. 

As the leading partner in all things audio, we democratize access to this powerful medium. Whether you’re leveraging the emotional depth of a host-read ad on the SiriusXM Podcast Network or the speed and efficiency of a synthetic voice ad on AudioGo, it’s here where you can connect with 170M monthly listeners and create a powerful audio strategy that’s as dynamic as the market itself. 2 Let’s chat.

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