SLNG.ai, a speech infrastructure startup out of Barcelona building the first radically global platform for voice AI, today announced it has raised €3.3 million in pre-Seed funding to challenge the US-centric voice technology ecosystem that “has left billions of users worldwide in digital silence.“
The round, led by Earlybird VC, will accelerate SLNG’s plan to provide developers, startups, and enterprises with a unified platform that integrates multiple speech models, supports true global deployment with regional compliance, and eliminates the barriers that have kept voice technology concentrated in a handful of languages and markets.
According to Luke Miller, CEO and Co-founder of SLNG: “We’re not just building another voice AI platform, we are rethinking the entire ecosystem to be developer first, truly global and compliant.“
The pre-Seed round raised by SLNG reflects growing investor attention in Europe’s voice and speech technology sector during 2025.
The landscape includes funding rounds such as Vox AI’s €7.5 million Seed to expand multilingual voice assistants for quick-service restaurants, Synthflow AI’s €17.2 million Series A for enterprise-grade voice agents, and Solda.AI’s €3.5 million Seed for telesales automation.
Other adjacent raises include Augmented Hearing’s €3 million Seed for speech enhancement and MEGA’s €1.7 million pre-Seed to build compliant AI voice agents.
Against this backdrop, SLNG’s Barcelona base makes it one of the few Spanish entrants in the voice infrastructure field, contrasting with Northern European dominance in voice agents.
Unlike peers that build application-level conversational systems, SLNG focuses on model-agnostic voice infrastructure, offering developer tools to integrate multiple speech models and maintain regional compliance. The raise positions SLNG as an early mover in the foundational layer of Europe’s speech ecosystem – complementary to, rather than competing directly with, voice agent startups driving the broader 2025 funding trend.
“What excites us about SLNG is the audacity of their mission: to make voice AI universal, compliant, and developer-first from day one. Luke and the team are not just building a product – they’re building the missing infrastructure for a truly global voice ecosystem. We believe SLNG can define the next era of speech technology,“ added Akash Bajwa, Principal at Earlybird VC.
SLNG was founded in 2025 by Ismael Ordaz and Luke Miller. Ordaz leads product and engineering, while Miller scales GTM like he did at companies like npm and Vercel. Having seen speech AI break beyond US borders: models failing on dialects, compliance blocking markets and costs spiraling out of control, they built SLNG to “unmute the world”.
The startup was founded to address repeated patterns that companies continuously struggle with:
- Lack of regional compute
- Missing industry-specific models
- Compliance barriers
- Latency issues
According to SLNG, most platforms optimise primarily for premium languages like English, Spanish, and French, leaving other languages/dialects as afterthoughts. High latency and data residency issues entangle deployment in many non-US centric regions.
Developers are forced into single-provider ecosystems with limited flexibility in terms of cost and model testing. Lastly, regulated industries can’t deploy voice AI products due to data sovereignty requirements that existing platforms simply can’t meet.
Unlike traditional speech AI providers, SLNG offers a model-agnostic platform where developers integrate any speech-to-text, text-to-speech, or voice cloning model through a single API.
The company’s open ecosystem approach lets developers combine open-source and proprietary models without vendor lock-in, while developer-first design delivers SDKs and APIs built for rapid integration. This avoids months-long implementations, giving developers unprecedented flexibility in building voice-enabled applications.
The platform already supports deployment across over 20 regions, enabling companies in regulated industries, like healthcare, finance, and government, to finally deploy voice AI while meeting strict data residency requirements.
Read the orginal article: https://www.eu-startups.com/2025/10/unmuting-the-world-spains-slng-raises-e3-3-million-to-challenge-us-centric-speech-ai-infrastructure/
