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Launch HN: Issen (YC F24) – Personal AI language tutor

313 points mariano54 | 1 comments | 26 Jun 25 14:32 UTC | HN request time: 0.201s | source

Hey HN, we're Mariano and Anton from ISSEN (https://issen.com), a foreign language voice tutor app that adapts to your interests, goals, and needs.

Demo: https://www.loom.com/share/a78e713d46934857a2dc88aed1bb100d?...

We started this company after struggling to find great tools to practice speaking Japanese and French. Having a tutor can be awesome, but there are downsides: they can be expensive (since you pay by the hour), difficult to schedule, and have a high upfront cost (finding a tutor you like often forces you to cycle through a few that you don’t).

We wanted something that would talk with us — realistically, in full conversations — and actually help us improve. So we built it ourselves. The app relies on a custom voice AI pipeline combining STT (speech-to-text), TTS (text-to-speech), LLMs, long term memory, interruptions, turn-taking, etc. Getting speech-to-text to work well for learners was one of the hardest parts — especially with accents, multi-lingual sentences, and noisy environments. We now combine Gemini Flash, Whisper, Scribe, and GPT-4o-transcribe to minimize errors and keep the conversation flowing.

We didn’t want to focus too much on gamification. In our experience, that leads to users performing well in the app, achieving long streaks and so on, without actually getting fluent in the language you're wanting to learn.

With ISSEN you instantly speak and immerse yourself in the language, which, while not easy, is a much more efficient way to learn.

We combine this with a word bank and SRS flashcards for new words learned in the AI voice chats, which allows very rapid improvement in both vocabulary and speaking skills. We also create custom curriculums for each student based on goals, interests, and preferences, and fully customizable settings like speed, turn taking, formality, etc.

App: https://issen.com (works on web, iOS, Android) Pricing: 20 min free trial, $20–29/month (depending on duration and specific geography)

We’d love your feedback — on the tech, the UX, or what you’d wish from a tool like this. Thanks!

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itake ◴[26 Jun 25 15:51 UTC] No.44388565[source]▶
I'm trying to learn vietnamese, but the lessons are really really rough and borderline bad advice.

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AI: Anh mệt is good if bạn are a man speaking about yourself. You can also say, “Em mệt” if you’re a woman.

this isn't correct. If you are of "older brother" age and are male, you say Anh. Em is for if you are "younger person" (does not matter the gender). Women tend to prefer being called "em" (even if they are older), because women prefer to be identified as younger than their true age... But that doesn't mean you can't call younger men em.

A good tutor would know your age relative to theirs and explain this context.

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It would say english phrases with a vietnamese accent.

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It also would give me really complex vietnamese phrases that I am not ready for. when I prompt for an explaination or translation, it would get off track from the original thing we were learning.

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Way more people in Vietnam (and the globe) speak southern Vietnamese, but the tutors seem to be from north Vietnam.

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The STT also was very forgiving if I pronounced things incorrectly. Or it would confuse english and vietnamese. I would say, "Phai", but it heard "bye"

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I was ready to pull out my credit card, but I can't trust it to teach me the right information. I pay $160/mo for Vietnamese tutoring ($20 per class). This would be way cheaper and I don't have to schedule my classes.

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tempodox ◴[26 Jun 25 16:03 UTC] No.44388689[source]▶
This sounds very much like the kinds of mistakes that LLMs typically make. It's a pity, I would love a good language learning platform.
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Velorivox ◴[26 Jun 25 18:12 UTC] No.44389828[source]▶
A fundamental problem with language learning built around an LLM is that the one thing you can guarantee is that no two people will have a consistent experience, nor is there ever going to be a 100% freedom-from-error. That makes it very hard to predict and therefore market what or how people will learn.

I think this company will end up pivoting into a B2B context before long. Hopefully they will still stick to the mission, but who knows (and I wouldn't fault them if they don't – survival comes first).

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1. jamager ◴[27 Jun 25 09:31 UTC] No.44395276[source]▶
> nor is there ever going to be a 100% freedom-from-error

That is not a problem. Language is messy, you don't need 100% accuracy to learn. The problem is that LLM errors are fundamentally different from human errors, and you won't even know how to recognize them.

Your interlocutors can work around human errors, because they tend to follow the same patterns in same language. But they will freak out with LLM errors.