Programmable Voice for Enterprise Communications
Extend your communication strategy beyond SMS with automated voice delivery — text-to-speech notifications, voice OTP fallback, and outbound campaigns over global PSTN infrastructure.
Text-to-Speech Delivery
Text-to-speech (TTS) voice delivery converts written message content into spoken audio, delivered directly to a recipient's phone via a standard voice call. This is ideal for notifications, alerts, and reminders where the spoken word provides a stronger call to action than a silent text message.
Our TTS engine supports natural-sounding speech synthesis across multiple languages and regional accents, ensuring your automated voice messages are clear, professional, and appropriate for your target audience. Scheduled delivery capabilities allow you to reach recipients at optimal times, and delivery confirmation webhooks close the loop on every call attempt.
Discuss RequirementsKey Capabilities
- Multiple language and regional accent support
- Natural-sounding neural voice profiles
- Scheduled delivery at specific times
- Delivery and answer confirmation webhooks
- Retry logic for unanswered calls
- Text template with variable substitution
- Call duration and outcome reporting
- REST API integration with full documentation
Voice OTP & Verification
Voice OTP provides a critical fallback authentication channel for users who cannot receive SMS — whether due to poor mobile coverage, SMS filtering, or personal preference. Spoken authentication codes deliver the same one-time password security as SMS, through the universally accessible voice channel.
Voice OTP integrates seamlessly as a fallback when SMS delivery fails, ensuring your authentication flow never breaks. The system automatically detects SMS delivery failure and triggers a voice call carrying the same code, spoken clearly and repeated for accessibility. GDPR-compliant processing ensures all authentication data is handled lawfully with no persistent storage of sensitive content.
Discuss RequirementsKey Capabilities
- Automatic fallback from failed SMS delivery
- Multiple language delivery for international users
- Retry logic with configurable attempt limits
- GDPR-compliant data handling
- Clear speech synthesis for numeric codes
- Repeat and keypress confirmation options
- Real-time delivery status webhooks
- SLA-backed enterprise agreements
Outbound Voice Campaigns
Outbound voice campaigns enable automated telephone notifications at scale — from appointment reminders and service alerts to emergency broadcasts and customer notifications. Each call is personalised from a data-driven template and delivered reliably over global PSTN infrastructure.
Our API-driven outbound voice platform gives your application full control over call scheduling, content, and escalation logic. Answer detection distinguishes between live picks and voicemail, enabling context-appropriate message delivery. Call status tracking provides real-time visibility of campaign performance, with outcome data available via webhook and dashboard reporting.
Discuss RequirementsKey Capabilities
- Global PSTN connectivity, 190+ countries
- Answer machine detection and handling
- Call status tracking and outcome reporting
- API-driven campaign management
- Dynamic content with variable substitution
- Configurable retry and escalation rules
- Voicemail fallback messaging
- Campaign analytics and export
Voice Solutions — Frequently Asked Questions
What is voice OTP and when should I use it?
Voice OTP delivers a one-time authentication code as a spoken message via a telephone call, rather than as an SMS. You should use it as a fallback when SMS delivery fails — for example, when a user's number is on a network with poor SMS delivery rates, when SMS is filtered or blocked, or when a user requests a voice call as their preferred authentication channel. It ensures your login and verification flows never completely fail due to SMS unavailability.
Which languages does your text-to-speech system support?
Our TTS engine supports a wide range of languages including English (UK and US), French, German, Spanish, Portuguese, Arabic, Hindi, and many others. We use neural speech synthesis for natural-sounding delivery. If you have a specific language requirement, contact our team and we can confirm support and provide audio samples for quality assessment.
How does answer machine detection work?
Our outbound voice system uses audio analysis to detect whether a call is answered by a live person or an answering machine within the first few seconds of the call connecting. If a live person answers, the message is delivered immediately. If voicemail is detected, the system can leave a pre-recorded voicemail message or hang up and retry — behaviour is configurable per campaign.
Can voice calls be used alongside SMS in the same workflow?
Yes. Our platform is designed to support multi-channel workflows where voice acts as a fallback or supplementary channel. Your application can trigger an SMS first and, if delivery is not confirmed within a defined window, automatically escalate to a voice call. This pattern is widely used for OTP delivery, critical alerts, and appointment reminders where delivery assurance is paramount.
What coverage does your voice platform provide?
Our voice platform connects to global PSTN infrastructure covering 190+ countries. Coverage depth varies by market — in most major markets we provide direct carrier connections for maximum quality and reliability. For enterprise deployments with specific country requirements, we conduct a pre-sales coverage assessment to confirm route availability and quality before onboarding.
Ready to Add Voice to Your Communications Stack?.
Our team will scope a voice solution that fits your delivery requirements, target markets, and existing messaging infrastructure.