Voicebot speech-to-text

Choose the STT provider and model for a Sinch Voice channel.

Configure speech-to-text for your voicebot

When callers speak to your voicebot, Chatlayer converts speech to text with a speech-to-text engine.

You choose the provider and model per Sinch Voice channel from the channel Settings tab.

Open Sinch Voice channel settings

Speech-to-text settings apply to a Sinch Voice channel only.

Other channel types use their own settings elsewhere.

1

Go to Channels.

Open the Sinch Voice channel you want to configure.

2

Open the Settings tab.

Choose an STT provider

Under Speech-to-text, you can configure:

• STT provider — the engine that transcribes caller speech.

• Google STT model — shown only when Google is selected.

Use STT provider to pick the engine for this channel:

• Microsoft — default option. Uses Microsoft speech-to-text.

• Google — uses Google Cloud Speech-to-Text v2. You can also choose a Google model.

Changes save immediately when you select a new provider.

STT provider is set per Sinch Voice channel.

If you run multiple voice channels, each channel can use a different provider.

Choose a Google STT model

When you select Google as the provider, an extra dropdown appears.

Choose the model that fits your use case:

• Chirp 3 — default Google model. Good for most voicebots.

• Chirp 2 — earlier Chirp model. Useful for specific compatibility needs.

• Telephony — optimized for phone-call audio.

If you switch back to Microsoft, Chatlayer does not use the Google model until you select Google again.

If speech-to-text fails during a call, review the issue in Execution logs.

Improve recognition with phrase lists

You can submit a custom phrase list to improve recognition accuracy. To create a phrase list, open a support ticket and submit your list there.

This works well for names, addresses, product names, and domain-specific terms. For example, if your list includes Chatlayer, recognition prefers Chatlayer over chat layer.

You can submit phrase lists:

• per bot language

• or globally across all bot languages

Each list supports up to 500 phrases. Submit the list as a plain text file. Separate each phrase with a semicolon: ; Remove duplicate phrases before sending.

Related settings

On the same Sinch Voice channel Settings tab, the Recording section lets you enable Save recordings to store full call recordings automatically.