ARIA Live Region Implementation

I need to implement ARIA live regions for accessibility.

**Dynamic Content Types:**
[List all dynamically updating content]

**Announcement Needs:**
- Form validation errors: [yes/no]
- Loading states: [yes/no]
- Toast notifications: [yes/no]
- Real-time updates: [yes/no]
- Chat messages: [yes/no]

**Current Implementation:**
```jsx
[paste relevant code]
```

**Screen Reader Testing:**
- Tested with: [NVDA/VoiceOver/JAWS/none]
- Current issues: [describe problems]

Please provide:
1. Live region setup for each content type
2. Politeness level recommendations
3. Atomic vs non-atomic decisions
4. Implementation code examples
5. React hook for announcements
6. Testing methodology
7. Common pitfalls to avoid