Czech voice control in Home Assistant: models and custom sentences

Local vs. cloud models

Speech recognition (STT) ran locally through Whisper on an Intel NUC, the default model faster-whisper small-int8, Czech. Synthesis (TTS) through Piper, locally the cs_CZ-jirka-medium voice.

The local model handled simple things, but its Czech comprehension was noticeably worse and the response slower. In the end cloud recognition through Nabu Casa stayed; the local Piper can still be used for synthesis.

Custom sentence architecture

Control splits into two layers:

• ▸ Sentences / Hassil intents in custom_sentences/cs/ – recognition of sentences and slots only. One file per topic (energy.yaml, tv.yaml).
• ▸ Intent handling in packages/voice_control.yaml – intent_script with the actual HA actions.

configuration.yaml loads the packages:

homeassistant:
  packages: !include_dir_named packages

The intent name must be identical in both layers. Unknown intent AssistSetTvVolume means the sentence was recognised but no handler was found for it in intent_script.

Energy: power draw and consumption per period (23 October 2025)

The file custom_sentences/cs/energy.yaml recognises queries about the current power draw (optionally filtered) and about consumption over a period:

intents:
  EnergyGetPowerByFilter:
    slots:
      device_filter:
        optional: true
    data:
      - sentences:
          - 'Jaký je aktuální příkon'
          - 'Jaká je teď spotřeba'
      - sentences:
          - 'Jaký je aktuální příkon {device_filter}'
          - 'Jaká je teď spotřeba {device_filter}'
  EnergyGetEnergyPeriod:
    slots:
      period:
        required: true
    data:
      - sentences:
          - 'Kolik elektřiny {period}'
          - 'Jaká je {period} spotřeba'
lists:
  device_filter:
    values:
      - { in: 'shelly', out: 'shelly' }
      - { in: 'zásuvka|zásuvky|zásuvek', out: 'socket' }
      - { in: 'bojler', out: 'ariston' }
  period:
    values:
      - { in: 'dnes|dnešní', out: 'day' }
      - { in: 'tento týden|týdenní', out: 'week' }
      - { in: 'tento měsíc|měsíční', out: 'month' }

Handling EnergyGetPowerByFilter: with no spoken filter it uses the main Shelly 3EM sensor directly (device_class: power, state_class: measurement, unit W) and answers e.g. “Aktuální příkon celkem je 850 wattů.” With a filter it dynamically finds the power/active_power sensors matching {device_filter} and sums them.

EnergyGetEnergyPeriod maps {period} to sensor.energy_daily, sensor.energy_weekly and sensor.energy_monthly and returns consumption in kWh.

TV: volume and mute (30 October 2025)

The file custom_sentences/cs/tv.yaml handles two intents – setting the volume and toggling mute:

intents:
  AssistSetTvVolume:
    data:
      - sentences:
          - 'nastav hlasitost (televize|televizi|tv) (v|ve) {area} na {volume}'
          - 'dej (televizi|tv) (v|ve) {area} hlasitost {volume}'
  AssistToggleTvMute:
    data:
      - sentences:
          - '{toggle} [zvuk] (televize|televizi|tv) (v|ve) {area}'
lists:
  volume:
    range:
      from: 0
      to: 100
  toggle:
    values:
      - in: '(ztiš|ztlum|ztlumit|vypni zvuk|mute|umlč)'
        out: 'mute'
      - in: '(zapni zvuk|zruš ztlumení|unmute|zesil|zesílit)'
        out: 'unmute'

The {area} slot is an HA area, {volume} a number 0-100. The meaning is fixed by design – ztiš = mute, zesil = unmute – a mute toggle, not a gradual level change. Example command: “Nastav hlasitost televize v obýváku na 2.”

Handling AssistSetTvVolume: it converts the percentage to 0.0-1.0, finds the media_player.* in the area through area_id() and area_entities(), prefers an entity containing tv and, by supported_features, uses media_player.volume_set or the fallback volume_up/volume_down.

Mute is handled by the Philips TV (philips_js) integration, which does a real mute:

action: media_player.volume_mute
data:
  is_volume_muted: true

That beats volume_set or volume_up/down – on mute the TV keeps its original volume and restores it on unmute. Volume fallbacks cannot guarantee that.

Things to watch out for

• ▸ Hassil in: is not a YAML list. Writing in: ['ztiš', 'mute'] fails with TypeError: expected string or bytes-like object, got 'list'. Write each variant as its own value, or as an alternation a|b|c.
• ▸ Intent indentation. data: must be nested under the intent; a wrong indent makes loading fail with AttributeError: 'NoneType' object has no attribute 'get'.
• ▸ HA Jinja has no Python operators. Bitwise feats & 4 does not work; test a bit arithmetically, ((feats // 4) % 2) == 1. Replace the global abs(x) with the x | abs filter.
• ▸ Tell the error layers apart. “Při zpracování došlo k neočekávané chybě” means the intent was recognised but its HA action failed – not a sentence error.
• ▸ Check entity availability. Philips ConnectionFailure: All connection attempts failed is a problem of the integration talking to the TV, not of intent recognition. Before mute/unmute, call homeassistant.update_entity and do not send the action when the player is unavailable or unknown.

_Energy came first in October 2025, the TV followed a week later; the text was last updated on 30 October 2025._