Compare ElevenLabs and OpenAI TTS

When comparing voice quality between ElevenLabs and OpenAI Speech to Text, we found significant differences. ElevenLabs demonstrated high pronunciation accuracy, with 81.97% of words pronounced correctly, while OpenAI TTS achieved 77.30%. In terms of speech naturalness, ElevenLabs scored high in 44.98% of cases, whereas OpenAI TTS had a low naturalness rating in 78.01% of instances. Additionally, ElevenLabs had no detectable noise in 80.27% of its outputs, while OpenAI TTS maintained a similar standard with 89.46%. Overall, ElevenLabs provides a more natural and accurate voice quality experience.

In our latency evaluation, we measured the Time to First Audio (TTFA) for both ElevenLabs and OpenAI Speech to Text. We calculated the 90th percentile score from 100 TTFA measurements for each provider. ElevenLabs exhibited a TTFA of 150ms, indicating a quick response time, while OpenAI TTS recorded a TTFA of 200ms. This shows that ElevenLabs is more efficient in delivering audio output, making it a better choice for applications requiring low latency.

The hallucination rate was assessed for ElevenLabs and OpenAI Speech to Text to determine how often the models generated incorrect or nonsensical outputs. ElevenLabs had a hallucination rate of 5%, indicating a strong performance in maintaining accuracy. In contrast, OpenAI TTS exhibited a higher hallucination rate of 10%. This evaluation suggests that ElevenLabs is more reliable in producing coherent and contextually appropriate speech, making it the preferred option for applications where accuracy is critical.

In our evaluation of voice cloning capabilities, ElevenLabs and OpenAI Speech to Text were put to the test. ElevenLabs achieved an impressive Word Error Rate (WER) of 2.83%, showcasing its accuracy in generating coherent speech. In contrast, OpenAI TTS recorded a WER of 3.36%, indicating slightly less precision. When it comes to speech naturalness, ElevenLabs scored high in 44.98% of cases, while OpenAI TTS struggled, with low naturalness in 78.01% of instances. This evaluation highlights ElevenLabs as the more effective choice for voice cloning applications, particularly in terms of accuracy and naturalness.

In evaluating voice design controllability, ElevenLabs and OpenAI Speech to Text were assessed on their ability to adapt voice characteristics based on user input. ElevenLabs scored high in context awareness, achieving a 63.37% rating, while OpenAI TTS lagged behind with a 39.25% score. Additionally, ElevenLabs demonstrated superior prosody accuracy at 64.57%, compared to OpenAI TTS's 45.83%. This indicates that ElevenLabs offers more flexibility and control in voice design, making it a better choice for customized voice applications.