Hume AIが感情を理解する次世代TTSモデル「Octave 2」を発表！11言語対応で音声AIの新時代が幕開け

AI技術の進化は止まることを知らず、私たちの生活やビジネスのあらゆる側面に革新をもたらしています。中でも、テキスト読み上げ（TTS）技術は、その表現力の向上により、新たな局面を迎えています。そんな中、Hume AIが発表した次世代の多言語対応TTSモデル「Octave 2」は、感情を理解し、表現する能力で、まさに音声AIの未来を再定義しようとしています。

「Octave 2」とは何か？その驚異的な能力

Hume AIが2025年10月1日に公開した「Octave 2」は、単なるテキスト音声変換システムではありません。これは「スピーチ言語モデル」と呼ばれる、言葉の意味を文脈で理解し、感情、リズム、抑揚まで予測できる最先端のAIモデルです。 従来のTTSモデルが機械的な音声に終始していたのに対し、Octave 2は人間が話すような感情のニュアンスや個性を再現することが可能です。これにより、コンテンツに深みとリアリティをもたらし、リスナーをより強く惹きつけることができます。

主な特徴と革新的な機能

• 多言語対応の飛躍: 英語や日本語を含む11以上の言語に対応し、グローバルなコンテンツ制作やコミュニケーションに新たな可能性を開きます。アラビア語、フランス語、ドイツ語、ヒンディー語、イタリア語、韓国語、ポルトガル語、ロシア語、スペイン語など、多岐にわたる言語で超リアルな音声AIを提供します。
• 感情理解と表現力: テキストの感情的なトーンを深く理解し、喜び、悲しみ、怒り、皮肉といった複雑な感情を音声に反映させます。 特定の「演技指示」を与えることで、ユーザーが望む感情表現や話し方を細かく調整することも可能です。
• 驚異的な高速性と効率性: Octave 2は、応答時間が200ミリ秒未満と、40%高速かつ効率的です。これにより、リアルタイムでの会話型AIやインタラクティブなアプリケーションに最適です。 また、Octave 1と比較して半額のコストで提供され、経済性も向上しています。
• 新たな音声編集機能: 音声変換機能と直接的な音素編集機能が導入され、既存の音声の品質を維持したまま、声の変換や発音、タイミング、強調の微調整が可能になります。 これらの機能は、吹き替え、エンターテイメント、繊細なナレーションなど、多岐にわたる用途で活用が期待されます。
• 信頼性の高い発音: 珍しい単語、繰り返しのある単語、数字、記号なども、より確実に発音する能力を備えています。
• AIによる個性再現: 声の音色だけでなく、話者の個性を再現できるため、より人間らしい会話体験を生み出すことができます。

幅広い活用事例と未来への展望

Octave 2の登場は、様々な分野に革新をもたらすでしょう。

• コンテンツ制作: オーディオブック、ポッドキャスト、動画のナレーションにおいて、より感情豊かで魅力的な音声コンテンツを生成できます。
• リアルタイムコミュニケーション: AIアシスタント、チャットボット、電話応対システムなどで、より自然で共感的な対話を実現し、顧客体験を向上させます。 特に、SambaNovaとの提携により、SambaCloudプラットフォーム上での独占提供が開始され、エンタープライズ向けの高速かつ感情対応型AI音声が実現します。
• ゲームやエンターテイメント: ゲームキャラクターやAIコンパニオンに、豊かな感情表現と個性を持たせることが可能になります。
• アクセシビリティ: 視覚障がい者向けの読み上げ機能や、多言語学習ツールとして、より自然で理解しやすい音声を提供します。

Hume AIは、Octave 2の感情知能と多言語対応により、AIと人間のインタラクションをより人間らしく、そして効果的なものに変えることを目指しています。競合他社のElevenLabsとの比較テストでも、Hume AIの音声はオーディオ品質と自然さにおいて優位性を示しており、その技術力の高さがうかがえます。

今後、Hume AIが「The Hume Initiative」を通じて共感的AIに関する倫理ガイドラインを提唱しているように、技術の進歩と並行してその倫理的な側面にも配慮していくことが重要です。 しかし、Octave 2が切り開く音声AIの未来は、間違いなく私たちのコミュニケーションのあり方を豊かにし、新たな価値を創造するでしょう。感情を理解し、共感するAI音声が、私たちの日常に溶け込む日もそう遠くありません。

Octave 2: Hume AI’s Multilingual Breakthrough Ignites the Future of Emotionally Intelligent Voice AI – 11+ Languages, Real-time Control & Unprecedented Realism!

In a monumental leap forward for artificial intelligence and human-computer interaction, Hume AI has officially unveiled Octave 2, its next-generation multilingual Text-to-Speech (TTS) model. Launched on October 1, 2025, Octave 2 isn’t just an upgrade; it’s a paradigm shift, setting new benchmarks for voice realism, emotional intelligence, and global accessibility in synthetic speech. This innovation promises to redefine how we interact with AI, making digital voices virtually indistinguishable from human ones, across a diverse linguistic landscape.

The Dawn of Empathetic Multilingual Voices: Octave 2’s Core Innovation

Hume AI has long been at the forefront of developing emotionally intelligent AI voice technology, focusing on integrating nuanced vocal expression into its models. Octave 2 embodies this philosophy, evolving beyond traditional TTS systems that often produce monotonous, context-insensitive speech. Unlike its predecessors and many current market offerings, Octave 2 functions as a true speech-language model. This means it deeply understands not just the words being spoken, but also the underlying emotional tone, rhythm, and timbre of acting, allowing it to infer when to whisper secrets, shout triumphantly, or calmly explain a fact. This profound comprehension enables Octave 2 to reproduce the full personality of a speaker, extending far beyond mere vocal timbre.

Breaking Down the Language Barriers: 11+ Languages and Beyond

One of Octave 2’s most impactful features is its expansive multilingual support. The model now fluently extends Hume AI’s next-generation voice capabilities to 11 languages at launch, including Arabic, English, French, German, Hindi, Italian, Japanese, Korean, Portuguese, Russian, and Spanish. This broad linguistic reach is a game-changer for global communication, enabling truly natural and expressive AI voices in diverse markets. For instance, the model has demonstrated impressive Japanese language generation, capable of producing hyperrealistic speech with accurate emotional nuances and accents. Hume AI has also hinted at ambitious plans to support at least 20 languages in the coming months, promising an even wider global footprint.

The ability of Octave 2 to switch between languages and deliver convincingly human speech, even for phonetically distinct languages like Russian and Japanese, is a significant advance. This capability is poised to revolutionize applications ranging from real-time translation tools to multilingual content creation, offering unparalleled authenticity and engagement for a global audience.

Beyond Words: Capturing Emotion and Personality

What truly sets Octave 2 apart is its refined ability to understand and generate emotional context. Building on the foundation of the original Octave model, which introduced context-aware and emotionally nuanced speech, Octave 2 further deepens this understanding. It doesn’t just convert text; it interprets the script’s intent, adjusting its tune, rhythm, and cadence to convey emotions like joy, frustration, sarcasm, or urgency without explicit direction. This makes AI-generated speech not only natural but also genuinely engaging, replicating the subtle emotional cues that are intrinsic to human communication. Users can even provide descriptive prompts to design unique AI voices specifying characteristics such as accent, age, gender, and emotional tone, offering unparalleled flexibility for creators.

Unprecedented Control: Voice Conversion and Phoneme Editing

Octave 2 introduces two groundbreaking features that provide unparalleled granular control over synthesized speech: realistic voice conversion and direct phoneme editing.

Seamless Voice Conversion: New Frontiers in Dubbing and Content Creation

The voice conversion capability allows users to exchange one voice for another while meticulously preserving the phonetic qualities and timing of the original spoken utterance. This is a transformative tool for industries requiring consistent voice identities across different languages or scenarios. Imagine dubbing a film into a new language while retaining the original actor’s distinct vocal characteristics, or seamlessly integrating precise human touch-ups into AI voiceovers without any discernible shift in vocal identity. This feature opens up a wealth of creative possibilities, enhancing the authenticity of localized content and streamlining production workflows in entertainment, advertising, and e-learning.

Granular Precision: The Power of Phoneme Editing

Direct phoneme editing offers an even finer level of control, enabling granular replication and editing of individual phonemes. This level of precision was previously difficult, if not impossible, to achieve with text input alone. This feature empowers creators to fine-tune pronunciation, timing, and emphasis with extreme accuracy, making it invaluable for scenarios demanding absolute phonetic fidelity, such as specialized linguistic training, audio branding, or creating highly specific character voices. While these advanced features are “set to arrive shortly” or “available soon” on the platform, their potential impact is immense.

Speed, Efficiency, and Accessibility: The Technical Edge

Beyond its advanced features, Octave 2 delivers significant improvements in performance and cost-efficiency. It boasts a 40% increase in speed compared to its predecessor, generating audio responses in under 200 milliseconds. This ultra-low latency is crucial for real-time interactive experiences, such as conversational AI, live translation, and voicebots, where delays can significantly diminish user satisfaction.

This impressive speed was achieved without compromising quality, thanks to Hume AI’s strategic deployment of Octave 2 on some of the world’s most advanced chips for large language model (LLM) inference. The company collaborated closely with SambaNova, a leader in next-generation AI infrastructure, to develop a new inference stack specifically optimized for Octave 2’s novel speech-language model architecture. Furthermore, Hume AI has made Octave 2 more accessible by offering it at half the price of Octave 1, with the potential for even further cost reduction for dedicated deployments. This efficiency and affordability are critical for powering large-scale applications across various sectors.

Real-World Impact: Transforming Industries

The capabilities of Octave 2 promise to revolutionize numerous industries:

• Entertainment & Gaming: Developers can create dynamic, emotionally rich character dialogues that adapt to in-game contexts, enhancing immersion. Voice conversion can facilitate seamless dubbing for global releases, maintaining vocal consistency.
• Customer Service & Virtual Assistants: AI agents can now communicate with unprecedented empathy and personality, leading to more engaging and satisfying customer interactions in multiple languages. Real-time, low-latency responses minimize frustration and improve service efficiency.
• Content Creation: Podcasters, audiobook narrators, and video producers can generate high-quality, expressive voiceovers in various languages, with the ability to fine-tune pronunciation and emotional delivery for perfect storytelling. Multi-speaker conversation features allow for instant podcast creation with diverse AI personalities.
• Real-time Translation & Conversational AI: Octave 2’s multilingual support and low latency make it ideal for real-time translation systems and sophisticated conversational interfaces, enabling truly natural cross-lingual communication.

The Future of Human-AI Interaction

Hume AI’s Octave 2 represents a significant milestone in the journey towards more natural, empathetic, and globally accessible AI. By combining hyperrealistic voice synthesis with deep emotional understanding and unprecedented control features, Hume AI is not just advancing technology; it’s shaping the future of human-AI interaction. The company’s commitment to emotionally aware AI systems, coupled with its support for initiatives like “The Hume Initiative” which publicizes ethical guidelines for empathic AI, underscores a responsible approach to these powerful advancements.

As AI continues its rapid evolution, innovations like Octave 2 highlight the immense potential for technology to bridge cultural and linguistic divides, fostering more meaningful and impactful connections between humans and machines. The era of truly expressive, multilingual AI voices is not just on the horizon; it has arrived, ready to transform our digital world.