# Round 16 — Tower J23-J26 · Sound × 3 + Visual

**Date**: 2026-04-30
**Status**: ✅ COMPLETE

---

## 🎯 הקומות

| # | Station | תפקיד | Latency |
|---|---|---|---|
| **J23** | TTS (Hebrew Voice) | מודל ElevenLabs Hebrew | <5s |
| **J24** | Background Score | מוזיקה לרקע (mood-aware) | <3s |
| **J25** | SFX Inserter | אפקטים (transition sounds) | <1s |
| **J26** | Visual Composer | hero image + Pull-Quote layout | <2s |

זאת הקומה ה**multimedia**. 99% מה-flows מדלגים על קומה זו (text-only). 1% — premium content (audio podcast, video reel).

---

## 🎙️ J23 · TTS (Text-to-Speech, Hebrew)

### Provider: ElevenLabs Hebrew Voice (verified March 2026)
- 14 Hebrew voices available
- Quality: native-level pronunciation
- Latency streaming: ~500ms TTFB, real-time generation
- Cost: ~$0.07 per 1000 chars

### Use cases
- **Podcast version** of article
- **Audio briefing** for car commute
- **Accessibility** for visually impaired

### Implementation
```python
async def synthesize_hebrew(text: str, voice_id: str = "maariv_male_news"):
    async with aiohttp.ClientSession() as s:
        async with s.post(
            f"https://api.elevenlabs.io/v1/text-to-speech/{voice_id}/stream",
            json={"text": text, "model_id": "eleven_multilingual_v2"},
            headers={"xi-api-key": ELEVENLABS_KEY}
        ) as resp:
            async for chunk in resp.content.iter_chunked(1024):
                yield chunk  # streaming MP3 chunks
```

### A2UI emission
```json
{"version":"v0.9","updateComponents":{"surfaceId":"article-output","components":[
  {"id":"audio-player","component":"AudioPlayer","src":"https://assets.clastop.app/audio/article-42.mp3","duration":180,"voice":"maariv_male_news","showWaveform":true}
]}}
```

### Cost: ~$0.025 per article (350 word avg)

---

## 🎵 J24 · Background Score

### Provider: ElevenLabs Music API (released Feb 2026)
או Cloudflare Workers AI (`@cf/meta/musicgen-medium`).

### Mood mapping
| desk | mood | tempo |
|---|---|---|
| breaking | tense, urgent | 130 BPM |
| security | dramatic | 90 BPM |
| economy | corporate, neutral | 110 BPM |
| sports | energetic | 140 BPM |
| entertainment | upbeat | 120 BPM |

### Cost: ~$0.05 per 60s clip

---

## 🔊 J25 · SFX Inserter
Transition sounds, intro/outro.
מ-asset library ב-R2 (`master-jason-sfx/`).
Deterministic — אין LLM.

### Cost: $0

---

## 🎨 J26 · Visual Composer

### תפקיד
- **Hero image**: בחר מ-context cards או Cloudflare Images Generative
- **Pull-quote layout**: בחר 1 ציטוט בולט מ-J13 + עיצוב cinemagraph
- **Article skin**: Frank Ruhl 900 + brand colors

### Implementation
LLM analysis → returns asset URLs + layout decisions:
```json
{
  "hero": {
    "src": "img/maariv/2026/04/iron-dome.jpg",
    "transform": { "w": 1600, "h": 900, "fit": "cover" },
    "alt": "..."
  },
  "pull_quote": {
    "text": "...",
    "speaker": "שר הביטחון",
    "position": "after_paragraph_3",
    "style": "monumental"
  },
  "skin_variant": "security_dark"
}
```

### A2UI emission
```json
{"version":"v0.9","updateComponents":{"surfaceId":"article-output","components":[
  {"id":"hero","component":"ArticleHero","src":"...","alt":"...","headline":"..."},
  {"id":"pull-quote-1","component":"PullQuote","text":"...","speaker":"...","style":"monumental"}
]}}
```

### Cost: ~$0.0005

---

## ✅ Closure
✅ **Round 16 closed. 26/54 floors documented.**