Prosodic Speech Control Implementation (Speed, Pitch, Volume)

Implementation of prosodic speech control (speed, pitch, volume) Prosody—rhythm, tempo, intonation, and volume of speech. Precise prosody control allows for context-specific synthesis: slower for numerical data, louder for warnings, higher pitch for questions. ### SSML prosody control

<speak version='1.0' xmlns='http://www.w3.org/2001/10/synthesis' xml:lang='ru-RU'>
  <!-- Скорость: x-slow, slow, medium, fast, x-fast, или % -->
  <prosody rate="slow">
    Номер вашего заказа: А-один-два-три-четыре.
  </prosody>

  <!-- Тональность: x-low, low, medium, high, x-high, или ±st -->
  <prosody pitch="+2st">
    Это хорошая новость!
  </prosody>

  <!-- Громкость: silent, x-soft, soft, medium, loud, x-loud, или дБ -->
  <prosody volume="loud">
    Внимание!
  </prosody>

  <!-- Комбинированное управление -->
  <prosody rate="90%" pitch="-1st" volume="-3dB">
    Подождите, пожалуйста, один момент.
  </prosody>
</speak>
```### Dynamic management at runtime```python
from dataclasses import dataclass

@dataclass
class ProsodyProfile:
    rate: str = "medium"    # x-slow | slow | medium | fast | x-fast | 80%
    pitch: str = "medium"   # x-low | low | medium | high | x-high | +2st
    volume: str = "medium"  # silent | x-soft | soft | medium | loud | x-loud

PROFILES = {
    "numbers": ProsodyProfile(rate="slow", pitch="medium"),
    "warning": ProsodyProfile(rate="medium", pitch="+2st", volume="loud"),
    "farewell": ProsodyProfile(rate="slow", pitch="-1st"),
    "question": ProsodyProfile(pitch="+1st"),
}

def wrap_with_prosody(text: str, profile: ProsodyProfile) -> str:
    return f"""<prosody rate="{profile.rate}" pitch="{profile.pitch}"
                        volume="{profile.volume}">{text}</prosody>"""
```### Contextual management via NLP```python
def detect_prosody_context(text: str) -> ProsodyProfile:
    """Автоматически определяем нужную просодику"""
    if text.endswith("?"):
        return PROFILES["question"]
    if any(w in text.lower() for w in ["внимание", "важно", "срочно"]):
        return PROFILES["warning"]
    if any(char.isdigit() for char in text):
        return PROFILES["numbers"]
    return ProsodyProfile()  # default
```### Provider Restrictions - **Google TTS**: Full Support `<prosody> ` via SSML - **Azure**: `rate` in the range of 0.5–2.0, `pitch` ±50% - **OpenAI TTS**: only the `speed` parameter (0.25–4.0), without SSML - **Yandex SpeechKit**: the `speed` parameter via API, limited by SSML Timeframe: basic prosody management — 1–2 days. Contextual automatic routing — 3–4 days.