Text To Speech And Voices In DialNexa - DialNexa Documentation

Text to speech in DialNexa is what the caller actually hears. It turns the model’s reply into audio through a selected voice, language, voice model, speed, stability, volume, and provider path. A voice can make a correct answer feel helpful, rushed, unclear, or strangely formal.

DialNexa voice selector showing voice filters, sample playback, Nexa voice ID copy button, and row language selection.

DialNexa voice settings popover showing voice model, speed, stability, and volume controls for a selected voice.

The caller does not hear your provider architecture. They hear a voice saying their name, amount, date, and next step. Test those words.

Choose DialNexa Text To Speech And Voice Providers

Provider	Use it when	Test before publishing
ElevenLabs	You want broad voice auditioning, strong speaker personality, and a familiar provider for brand voice work.	Flash v2.5 behavior, names, numbers, speed, stability, and long compliance lines.
Cartesia	You want fast streamed speech, clean call audio, and language-aware voice output.	Language fit, volume, speed, and repeated short phrases.

For provider background, use the ElevenLabs integration catalog page. Cartesia voices are selected from the DialNexa voice selector.

Choose ElevenLabs
Choose Cartesia
Compare providers

Choose ElevenLabs when the voice personality matters and you want to audition a wider library. In the current dashboard path, ElevenLabs agent versions are standardized on Flash v2.5 (eleven_flash_v2_5) where supported, so treat that as the main model to test.

Choose Cartesia when fast, clean streamed speech matters more than a highly dramatic voice. Test through the actual phone path, not only through sample playback. Model: sonic-2.

How The Voice Selector Works

The selector is designed for large voice libraries.

UI control	What it does
Provider filter	Shows all public voices, or only the voices from one provider (ElevenLabs or Cartesia).
Language filter	Filters by languages supported by available voices. English is the starting filter in the current modal.
Gender filter	Narrows visible rows to male or female where the voice record includes that label.
Accent filter	Uses provider-specific accent metadata exposed by the voice records.
Search	Matches voice name, provider voice id, internal voice id, `voice_` id, and `vel_` Nexa voice id.
Sample playback	Plays the sample recording for quick auditioning.
Nexa voice ID	Lets users copy the `vel_` voice id for notes or API-adjacent setup.
Row language selector	Picks the exact language for that voice before applying it to the agent.

Setting	What users change	Practical test
Voice Model	The synthesis model available for the current voice.	Start with the visible model choice for the selected voice. For ElevenLabs, test Flash v2.5 where shown.
Voice Speed	How quickly the agent speaks.	Read dates, amounts, phone numbers, and local names. Faster speech usually fails there first.
Voice Stability	How much variation the voice has. Lower values can sound more emotional; higher values can sound calmer.	Repeat the same line three times and check consistency.
Voice Volume	Output loudness in the call path.	Listen through speaker mode, headphones, and the actual telephony route.

Do not copy provider documentation numbers into DialNexa sliders. Use the UI values and test calls. The dashboard maps provider ranges before saving.

Audio Cache And Repeated Speech

Audio Cache stores synthesized audio for repeated phrases. It works best when the generated text, voice provider, voice id, voice settings, and output format repeat.

Cache-friendly phrase	Why it works
A fixed welcome line.	Same text and same voice configuration repeat across calls.
A compliance disclosure.	Usually identical and latency-sensitive.
A short confirmation.	Repeats often and starts quickly when cached.

Cache-unfriendly phrase	Why it misses
A line with caller name, amount, or time.	Variables change the text.
A long model-generated explanation.	The model may phrase it differently each turn.
A reply based on fresh API data.	External data changes the output.

Audio Cache loves repetition. If every sentence is personalized confetti, cache will politely sit there doing very little.

DialNexa does not store incomplete interrupted segments as reusable cache entries. A segment must finish cleanly and match the text that was sent for synthesis before it can become future cached audio.

Streaming Speech Continuity

For streamed voices, DialNexa buffers and plays synthesized segments in order so callers hear the response as a coherent sentence. This is especially important for fast Cartesia paths and multi-part ElevenLabs output, where chunks can finish at different times. Hindi punctuation is also treated as a sentence boundary for supported TTS segmentation, so Hindi and Hinglish responses can flush at natural pause points instead of waiting for only English punctuation.

Where Voice Quality Shows Up Outside The Call

Voice quality is not only a caller comfort issue. It changes whether downstream work is trusted.

Downstream work	Why voice quality matters	Helpful links
Written confirmations.	If the caller misheard a date or amount, the follow-up message may look surprising or wrong.	Email with Resend, Gmail.
Sales handoff.	A confident summary is less useful if the caller struggled to understand the agent.	HubSpot, Salesforce.
Support escalation.	The recording helps the support owner judge tone, not only the transcript text.	Zendesk, Intercom.
Repeated campaigns.	Cache-friendly fixed lines can reduce perceived delay on common phrases.	Audio Cache monitoring.

Voice Review Checklist

Test the first sentence

The welcome line sets trust. Check pace, pronunciation, greeting tone, and whether the voice fits the use case.

Test difficult words

Include brand terms, product names, locality names, acronyms, medicine names, plan names, and agent names.

Test numbers and dates

Amounts, due dates, order IDs, phone numbers, and appointment slots reveal speech issues quickly.

Test interruption recovery

Interrupt the agent during the greeting and check how naturally it resumes.

Review recording and transcript together

The transcript shows content. The recording shows delivery.

Supported Voices And Models

Review voice fields and model fields.

Speech Settings

Enable Audio Cache and tune speech behavior.

Multilingual And Hinglish Calls

Match voice, language, and transcriber.

Audio Cache Monitoring

Read cache evidence on the call detail page.

​Choose DialNexa Text To Speech And Voice Providers

​How The Voice Selector Works

​Voice Settings In The Popover

​Audio Cache And Repeated Speech

​Streaming Speech Continuity

​Where Voice Quality Shows Up Outside The Call

​Voice Review Checklist

​Related Reading

Supported Voices And Models

Speech Settings

Multilingual And Hinglish Calls

Audio Cache Monitoring

Choose DialNexa Text To Speech And Voice Providers

How The Voice Selector Works

Voice Settings In The Popover

Audio Cache And Repeated Speech

Streaming Speech Continuity

Where Voice Quality Shows Up Outside The Call

Voice Review Checklist

Related Reading