Apple and Google both provide support for offline speech-to-text using local models. Users can configure it to be fully offline.

The Murena Voice to Text service in /e/OS sends the user's audio to OpenAI which is hidden away in their terms of service:

https://community.e.foundation/t/voice-to-text-feature-using-open-ai/70509

Voice to Text feature using Open AI

Thank you a lot for your positive and supporting comments about our new /e/OS Voice-to-text! Regarding its implementation in /e/OS, I’d like to explain a few things to explain why we have chosen an OpenAI STT API to implement it and how it’s going to evolve in the future: What we have learned from our experimentations with STT models that run locally on the smartphone for speech recognition: they work quite poorly, they make a lot of mistakes in voice recognition they are not able to mix la...

/e/OS community
/e/OS is heavily marketed as private but in reality it has enormous privacy issues like this with their default apps and services. It's also heavily marketed as avoiding Google services but yet has privileged integration for Google services and connects to multiple by default.
/e/OS doesn't keep up with basic privacy or security patches for the OS or browser engine used not only for the default browser but also the WebView used by many apps including email clients and far more for rendering web-based content. For more info see https://discuss.grapheneos.org/d/24134-devices-lacking-standard-privacysecurity-patches-and-protections-arent-private.
Devices lacking standard privacy/security patches and protections aren't private - GrapheneOS Discussion Forum

GrapheneOS discussion forum

GrapheneOS Discussion Forum
/e/OS is not a threat to mass surveillance but rather significantly helps with it by making exploiting devices to extract data or take remote control over them far easier. They do not keep up with basic High and Critical severity patches. All devices sold by Murena are insecure.
Even on Pixels, /e/OS is extremely far behind on providing the current High and Critical severity privacy and security patches due to being so far behind on OS updates. They mislead users by setting a fake security patch level and changing the UI to mask what's happening.
Murena is a for-profit company and /e/OS is very clearly built and managed for the benefit of Murena. Despite this, /e/OS receives a huge amount of EU government funding. If you're an EU taxpayer, your money is being used to build this extraordinarily insecure and non-private OS.
@GrapheneOS Seriously, jealous of EU funding? Please. Stop kicking down to your colleagues and start kicking up to the real competitors

@djoerd @GrapheneOS

Evoking “jealousy” is a common response when one lacks relevant arguments whereas GrapheneOS does an excellent job of communicating to inform the public about ongoing scams, they are extremely dedicated, and very often respond with answers of several detailed paragraphs, they often respond with more answers than the person asking the question expects in the first place, but I'm sure you do better.

/e/OS are not colleagues of GrapheneOS, and the competitor is iOS that GrapheneOS respects.

@Xtreix @GrapheneOS welcome to Mastodon! Yeah, there seems to be a lot of jealousy and little respect.

@djoerd @Xtreix Governments shouldn't fund building products for companies to sell for profit. We wouldn't want to be beholden to governments, particularly ones moving towards making end-to-end encryption and secure devices illegal.

/e/OS and Murena are not colleagues or competitors. /e/OS massively rolls back privacy and security rather than improving them. They heavily misrepresent what they're providing and through that are scamming people. /e/OS is nearly the direct opposite of GrapheneOS.