Top 10 AI Voice Agent Development Companies
Last updated on November 5, 2025
Voice agents are relatively new technology. Most development companies can build demos. Few have shipped production systems that handle real call volumes, telephony quality constraints, and conversation failures at scale.
The expertise gap appears when systems go live. Latency degrades under load. Conversation flows that worked in testing break with real user patterns. Telephony integration reveals architectural decisions that can’t support production requirements.
Some companies bring experience from previous voice deployments. Others are building their first system on every project. The difference determines whether problems get solved quickly or become expensive rebuilds months into development.
What Makes Voice Agent Development Different
Voice introduces constraints that chat systems avoid:
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Latency requirements: Response times under 500ms determine whether conversation feels natural or robotic. Delays acceptable in text chat become jarring in voice interaction, requiring streaming architectures and optimized inference across STT, LLM, and TTS components.
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Speech recognition complexity: Background noise, accents, and overlapping speakers produce recognition errors requiring conversation-level repair strategies rather than simple retry logic. Telephony integration introduces 8kHz PSTN audio quality that degrades accuracy compared to web-based 16kHz streams, plus codec handling complexity for SIP trunking and IVR systems.
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Conversation mechanics: Text interfaces process complete messages while voice requires real-time turn detection through silence duration and prosody cues. Voice systems need mid-utterance interruption support (barge-in) and backchannel responses that acknowledge understanding without disrupting speaker flow.
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Production requirements: Systems must maintain latency optimization under concurrent call loads, implement conversation design accounting for recognition error patterns, provide fallback strategies when comprehension fails, and surface quality degradation through monitoring before customer complaints arrive.
Evaluating Voice Agent Development Partners
Voice agent development companies fall into three categories with different tradeoffs. Specialized developers focus exclusively on voice and bring deep technical expertise but may lack broader AI capabilities. Full-service consultancies handle complete implementations but often subcontract voice-specific work. Enterprise platforms deliver quickly through standardized approaches but constrain customization when requirements diverge from standard patterns.
Deciding Between Platforms and Custom Development
Voice agent platforms work for use cases that fit standard patterns without significant differentiation, where speed to market matters more than conversation quality, call volumes stay under 50K monthly, internal technical resources are limited, multi-channel requirements benefit from unified platforms, and risk tolerance favors validated solutions.
Custom development makes sense when voice interaction strategically differentiates the product, vertical requirements need domain expertise and custom conversation patterns, platform limitations appear in integration or compliance, call volumes justify investment (50K–100K+ monthly), code ownership matters for avoiding platform lock-in, or specific conversation design proves critical to business value.
The hybrid path starts with platforms for speed to validate value propositions quickly, accepts initial platform limitations as temporary constraints, then rebuilds with custom development once product-market fit proves the investment worthwhile.
What to Look for in Development Partners
Production voice agents require capabilities beyond demo functionality. Key evaluation areas:
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Voice specialization: Agents deployed at customer scale maintaining sub-500ms latency in production conditions. Conversation flows that sound natural when spoken. Recognition error handling for accents, background noise, overlapping speakers.
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Telephony integration depth: Production experience with SIP, IVR, call routing in phone systems. Codec handling for 8kHz PSTN audio degradation. Quality maintenance across different telephony carriers.
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Vertical expertise: Understanding of industry terminology, workflows, regulatory requirements. Portfolio examples in comparable domains. References from similar deployments.
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Technical validation: Architecture review covering STT/LLM/TTS integration, scaling approach, failure handling, monitoring systems. Proof of concept testing core challenges (typically $5K–25K for 2-4 weeks). Team experience and dedication (exclusive vs shared resources).
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Business fundamentals: Total cost of ownership including development, infrastructure, maintenance, future upgrades. Code and data ownership terms. Financial stability and customer retention track record. Post-launch support responsiveness.
Reference checks reveal actual performance beyond marketing claims. Specific questions about completion rates, escalation patterns, latency in real use, timeline/budget accuracy, problem handling, and hidden costs surface patterns even in positive references.
The Best AI Voice Agent Development Companies
1. Softcery – AI Engineering for B2B SaaS Founders
Softcery is an AI engineering partner for B2B SaaS founders. The company builds production-ready AI systems that other development teams consider too complex or estimate at 6+ months. Softcery specializes in delivering advanced AI implementations that combine speed with reliability, focusing on projects where conversation quality and technical sophistication determine product success.
Voice Agent Development Approach:
Softcery’s voice agent development follows a production-first methodology focused on shipping working systems quickly and maintaining production reliability standards. The approach skips lengthy discovery phases and starts with functional prototypes, so prototypes evolve into production systems through rapid testing and systematic refinement. Development emphasizes conversation quality under real-world conditions—handling interruptions, recognition errors, and edge cases that demos typically avoid. Performance focus maintains sub-1.5 second response times in production environments handling concurrent calls.
Portfolio and Key Customers:
For CaseGen, a legal intake platform serving US law firms, Softcery built an AI voice agent that automates after-hours client intake calls. The voice agent handles complex legal conversations with natural flow, processing hundreds of calls monthly across multiple law firms. It eliminates missed opportunities from calls outside business hours and improves case qualification accuracy through structured conversations. The implementation demonstrates Softcery’s capability to handle domain-specific legal terminology, navigate sensitive information disclosure requirements, integrate with existing practice management systems, and maintain conversation quality under production volumes where recognition errors and caller interruptions are common.
Additional client work spans production AI launches across legal tech, marketing automation, e-commerce, and CRM platforms. Projects include text-based conversational agents for customer support workflows, document processing systems extracting structured data from unstructured inputs, and full-stack B2B SaaS platforms where AI capabilities integrate deeply rather than functioning as isolated features. Client testimonials average 4.9/5 from founders at companies including Bullseye (acquired) and Proximo AI, with feedback emphasizing delivery speed, technical problem-solving, and production reliability.
Company Information:
Softcery operates as Softcery OÜ, registered in Tallinn, Estonia with registry code 16783794 and VAT number EE102662948. Founded in 2019, the team consists of focused senior engineers specializing in production AI implementations, working directly with clients rather than through account management layers.
2. SoluLab – Pioneering Blockchain & AI Innovation
SoluLab is a digital and technological solution provider specializing in blockchain, AI, IoT, mobile app, and web development. Founded by former Goldman Sachs and Citrix executives, the company positions itself as the #1 global enterprise blockchain development company and expert AI agent development company, delivering innovative solutions across healthcare, finance, retail, and IoT sectors with a focus on cutting-edge voice AI and conversational technologies.
Voice Agent Development Approach:
SoluLab uses Agile development with iterative approaches and client involvement from day one. Their voice agent development leverages IBM Watson ecosystem including Watson Conversation for dialogue management, IBM Speech-to-Text (STT) for voice recognition, IBM Text-to-Speech for natural voice output, and IBM Voice Gateway for orchestration and phone network integration. The company specializes in Interactive Voice Response (IVR) systems with true telephony integration, enabling phone call answering, user greeting over phone/SMS, appointment scheduling based on available time slots, and custom bot response training. Their technical approach emphasizes code reviews, automated testing, and flexible offshore development models. Focus areas include voice AI agents for conversions and sales, voice-activated chatbots, HIPAA-compliant healthcare voice systems, and API-based integrations for enterprise environments.
Portfolio and Key Customers:
SoluLab’s healthcare IVR system demonstrates true telephony-based voice agent capabilities. The system is a HIPAA-compliant bot answering machine using IBM Voice Gateway that answers phone calls, greets users, provides service information, and schedules appointments based on availability. For Amanbank, a leading Libyan bank, SoluLab integrated Voice AI into mobile banking to enhance customer engagement and streamline banking services. The Shadecraft IoT Smart Shade project showcases voice activation technology with Alexa compatibility, far-field microphones with noise cancellation, and natural language processing for autonomous operation.
Company Information:
SoluLab maintains offices in Los Angeles, California and headquarters in Ahmedabad, Gujarat, India. Founded in 2014, the company employs 250+ developers, designers, and innovators. Legal entities include SoluLab Inc. and SoluLab Private Limited. The company achieved CMMI Maturity Level 3 certification in October 2024 and received the GoodFirms Trusted Choice Award 2023, demonstrating commitment to quality and innovation in voice AI development.
3. Appinventiv – Empowering Digital Transformation
Appinventiv is a leading global mobile app development firm specializing in Generative AI and Voice AI agent development, empowering startups and Fortune 500 companies with cutting-edge digital transformation solutions. The company has delivered 300+ AI-powered solutions and maintains ISO 9001 and ISO 27001 certifications with GDPR and HIPAA compliance, positioning itself as a trusted partner for enterprise-grade voice AI implementations across healthcare, fintech, social media, and recruitment sectors.
Voice Agent Development Approach:
Appinventiv employs a comprehensive 8-step voice agent development process: strategic planning, user journey mapping, conversational design, voice optimization, technology selection, development & training, testing & deployment, and ongoing optimization. Their technical architecture integrates Automatic Speech Recognition (ASR) as “the ears of the agent,” Natural Language Understanding (NLU) for intent and context extraction, Large Language Models (LLMs) like GPT-4o for contextually relevant responses, Text-to-Speech (TTS) for natural-sounding voices, and dialogue management for context retention across conversations. Voice recognition for identity verification, data encryption, and GDPR/HIPAA compliance ensure enterprise security.
Portfolio and Key Customers:
The Vyrb project showcases Appinventiv’s voice AI capabilities: a voice-first social media wearable enabling users to post to Twitter and Facebook via Bluetooth glasses using voice commands, with Siri and Google Assistant integration, STT messaging, and real-time audio command processing. Results include $1+ million in funding secured, 50,000+ app downloads, and 40% increase in average app engagement time. For JobGet, the blue-collar recruitment platform, Appinventiv delivered intelligent matching algorithms and video interview capabilities, resulting in $52M Series B funding, 2 million downloads, 150,000 successful placements, and reducing job search time from 2-3 months to 2-3 weeks, earning the MIT Inclusive Innovation Award and MassChallenge Gold Award. Additional clients include Flynas (Saudi Arabian airline AI chatbot), MyExec (AI business consultant with GPT-4o and LangChain), and Mudra (millennial finance app with Google Dialogflow).
Company Information:
Appinventiv is headquartered in Noida, Uttar Pradesh, India. Founded in 2015, the company employs 1,500-1,600+ professionals. Legal entity: Appinventiv Technologies Pvt Ltd. The company earned recognition as Deloitte Tech Fast 50 (2023, 2024) and Economic Times Leader in AI Product Engineering, demonstrating sustained excellence in AI and voice agent development.
4. Avenga – Global Technology Partner
Avenga is an IT engineering and consulting platform specializing in custom software development and AI-first transformation, part of KKCG Group’s technology pillar. With 410+ clients served over 20+ years and 31 offices globally, Avenga delivers enterprise-grade AI solutions with particular strength in conversational AI, workplace automation, and IoT-enhanced voice experiences.
Voice Agent Development Approach:
Avenga’s voice agent development emphasizes privacy-first architecture design for enterprise compliance, multi-platform integration strategy across mobile apps and business chat services, and IoT sensor integration for enhanced context awareness. Their technical stack integrates conversational AI with Natural Language Processing (NLP) and (NLU), native mobile application development for iOS and Android with intuitive chat and voice functions, seamless Office365 and G-Suite calendar integration, and business chat platform deployment across Slack, Microsoft Teams, Workplace by Facebook, and Webex Teams. Focus areas include workplace voice AI assistants, multi-channel conversational interfaces spanning voice and chat, enterprise calendar and meeting management, IoT-enhanced voice experiences with occupancy and environmental monitoring, and privacy-first voice AI for regulated industries.
Portfolio and Key Customers:
The UMA AI project demonstrates Avenga’s voice agent capabilities: a scalable, privacy-first digital AI-powered assistant for modern workplaces integrating conversational AI, IoT sensors, and centralized management. The solution includes UMA Book with natural conversational AI voice control for meeting scheduling and Office365/G-Suite integration accessible via Slack, Teams, Workplace, and Webex with native chat and voice functions; UMA Sense with IoT sensors monitoring occupancy, temperature, air quality, and parking; and UMA Vision providing central management with business intelligence dashboards. Results include 3 core products successfully delivered, 100% private platform ensuring data security, unified interface orchestrating meeting space usage across enterprise systems, and native mobile applications with intuitive voice functions for iOS and Android.
Company Information:
Founded in 2019 through strategic consolidation of companies with operations dating back to 1992, the company employs 4,300+ digital transformation experts. Legal entity: Avenga International GmbH, registered at Cologne County Court HRB 97336, VAT ID: DE326832953. The company is wholly owned by KKCG Group (acquired February 2024 from Oaktree Capital Management and Cornerstone Investment Management), providing strong financial backing and strategic resources for enterprise AI development.
5. Impekable – End-to-End Product & Software Development Consultancy
Impekable is an award-winning product development consultancy creating impactful, elegant digital products. This design-forward consultancy combines enterprise-level engineering with design expertise through a small, senior, partner-led team delivering for startups to Fortune 500 companies. The company focuses on outcomes: faster deflection, lower support costs, and consistent caller experience.
Voice Agent Development Approach:
Impekable’s approach emphasizes design excellence plus technical implementation with a user-centered approach prioritizing elegance alongside functionality. The small senior team ships in tight loops and works directly with stakeholders. Strategic partnerships with Google Cloud and Twilio de-risk deployment and shorten time to value. The company focuses on tailored customer-service voice agents for 24/7 operation. An ElevenLabs partnership announced to accelerate enterprise voice AI adoption demonstrates Impekable’s commitment to staying at the forefront of voice technology.
Portfolio and Key Customers:
With 600+ projects for 250+ clients spanning Fortune 500 programs to startups, Impekable works across banking, insurance, retail, healthcare, and SaaS industries. Notable projects include Adobe XD’s official iOS 13 UI Kit, DigitalOcean’s first-ever Partner Directory, and custom chatbots and AI voice bots for order-taking, customer support, and workflow automation.
Company Information:
Impekable is located in Silicon Valley, San Francisco Bay Area, California. Founded in 2012, the company maintains a team of approximately 20 employees with geographic reach across the US, Europe, and Asia-Pacific.
6. Master of Code Global – Building Custom Voice to Solve Your Unique Challenges
Master of Code Global develops world-class custom digital experiences for web, mobile, chat, and voice solutions empowered by AI with an unwavering commitment to client success. The team of experts focuses on measurable business outcomes with transparent communication and security, serving clients with 1+ billion users through chatbot solutions.
Voice Agent Development Approach:
Master of Code Global follows an eight-stage transparent process: requirements understanding, NDA, discovery, development, QA & testing, launch, maintenance/scaling, and dedicated support. Their voice solutions engineering approach aims to “empower clients with effortless speech-enabled interactions that feel natural and convenient.” The company maintains ISO 27001 certification and focuses on conversational AI across multiple channels including voice.
Portfolio and Key Customers:
A hotel group case study demonstrates an 8.5 minute savings per guest request through a speech-enabled AI agent integrated with property management systems, accessible via in-room smart devices and mobile apps. The system recognizes industry terminology, local attractions, and hotel-specific amenities. An automotive voice agent for a major automotive group achieved 37% conversion growth, 26% increase in test-drives, and 357 after-sales engagements through a hands-free virtual assistant integrated with dealership management systems, available on mobile app, website, and WhatsApp. Additional implementations include large telecommunications company virtual assistants. Performance metrics include 56 NPS and 9.2 CSAT scores across 400+ projects delivered.
Company Information:
Master of Code Global is headquartered in Redwood City, California. Founded in 2004, the company employs 200-250+ professionals globally across 4 continents.
7. Azumo – Trusted to Ship Software from Startups to Fortune 100 Companies.
Azumo is a nearshore software development company bridging offshore cost-effectiveness and onshore alignment. The firm operates with U.S. time zone alignment, primarily with developers in South America. As a top-rated company specializing in AI-driven solutions across web, mobile, and data domains, Azumo brings unique advantages in cost structure and cultural alignment.
Voice Agent Development Approach:
Azumo follows a four-phase engagement model: Technical Foundation (“First Touch Deep Dive” with VP Engineering and CTO), Support Infrastructure (complete team with senior oversight, PMs, customer success), Continuous Monitoring (daily standups, weekly sprint reviews), and Built-in Redundancy (“Bench Strength Protocol” with reserve resources). The company’s AI-orchestrated development system claims 85% reduction in planning time. Proprietary tools include Charlibot (chatbot platform), Valkyrie (AI toolkit), and AI Schema Generator.
Portfolio and Key Customers:
Major clients include Facebook, Meta, Twitter, Omnicom, Discovery Channel, NCsoft, and United Health. The Discovery Channel “Quizcovery” project showcases Azumo’s voice capabilities: an Alexa Skill and Google Assistant Voice App using ACE (Azumo Conversational Engine) providing multi-lingual interactive trivia, becoming one of the top-rated Alexa Skills in Latin America. A gaming voice AI implementation for NCsoft demonstrates generative AI voice assistant capabilities. Additional work includes semantic search using GPT-2.0 for Meta and AI-driven anomaly detection for Phaidra. The Charlibot platform enables AI chatbots trainable in minutes and deployable on Slack, SMS, WhatsApp, and Facebook Messenger.
Company Information:
Azumo is headquartered in San Francisco, California. Founded in 2016, the company employs 62-250 professionals operating 100% remote with nearshore teams from Latin America (primarily Argentina). The company is Black Founded and Black Led with ~33% of the development team identifying as Black. Performance metrics include a 4.9-star verified rating, 93% promoter score, and 200% annual renewal retention.
8. Itransition – Global Software Engineering Company
Itransition is a trusted global software development company specializing in AI agent development with comprehensive capabilities spanning agentic AI solutions from copilots to fully autonomous agents. With 26+ years of experience delivering 1,600+ projects to 800+ customers across 40+ countries, Itransition brings enterprise-grade development processes, ISO 9001-backed quality management, and deep expertise in conversational AI, virtual assistants, and enterprise system integration.
Voice Agent Development Approach:
Itransition employs Agile frameworks including Scrum, Kanban, and Scrumban for small teams, with SoS, LeSS, and SAFe for larger implementations. The development approach encompasses both platform-based solutions and custom software, with AI audits of software ecosystems to select suitable tech stacks. Focus areas include conversational AI chatbots, virtual assistants, rules-based systems combined with LLM intelligence, medical voice transcription for clinical documentation, and GenAI-powered conversational systems with seamless integration into existing business applications.
Portfolio and Key Customers:
For a US-based insurance company, Itransition developed a virtual assistant optimizing employee onboarding that reduced onboarding costs and helped new employees deliver high-quality services by answering questions in human-like ways using the company knowledge base. A US-based medical clinic implementation features a voice transcription system that captures audio recordings of patient visits, creates complete transcripts, aggregates relevant data, and saves visit history in EHR format, reducing physician paperwork time significantly. The OpenAI medical question answering application demonstrates proof-of-concept capabilities for healthcare information access using the Davinci AI model.
Company Information:
Itransition is headquartered in Lakewood, Colorado with development centers across 6 continents. Legal entity: Itransition Inc., private company. With ISO 9001 certification and 26+ years of operational history, Itransition maintains enterprise-grade quality standards serving healthcare, insurance, financial services, manufacturing, and technology sectors with comprehensive AI and voice-enabled solutions.
9. Prismetric – Delivering Quality Products and Premium Services
Prismetric is a trusted AI voice solutions development firm specializing in AI-powered digital transformation services across healthcare, fintech, retail, logistics, and real estate sectors. The company positions itself as delivering tailored voice agents that match brand tone and customer journey requirements, building agents that scale effortlessly to handle thousands of simultaneous interactions for both startups and enterprises with 500+ successful product launches globally.
Voice Agent Development Approach:
Prismetric’s approach spans strategic consulting through optimization, including ROI analysis, custom development aligned with brand workflows, voice user interface (VUI) design, and NLP model fine-tuning for industry-specific language. Their technical architecture integrates ASR, NLP/NLU for intent extraction, and TTS for natural voice responses. Core capabilities include real-time processing for instant responses, contextual memory for prior interactions, self-learning mechanisms, 24/7 operations, and scalability handling thousands of simultaneous interactions. Services include pre-built solutions for healthcare, finance, and e-commerce, CRM/ERP/telephony integration, multilingual support in over 100 languages, and legacy IVR modernization.
Portfolio and Key Customers:
A voice-based shopping assistant for an e-commerce brand demonstrates Prismetric’s voice capabilities, handling order tracking, product inquiries, and returns with 24/7 availability. In healthcare, their voice agents automate appointment scheduling, patient follow-ups, and prescription reminders, reducing administrative workloads while improving patient experience in telehealth and clinic settings. Real estate implementations feature voice agents that qualify leads, schedule property viewings, and share listings, providing instant assistance to potential buyers. An AI-powered logistics coordinator uses voice to optimize delivery routes in real time. Major clients include Macy’s, Airtel, Peugeot, and Singapore Post.
Company Information:
Prismetric is headquartered in Gandhinagar, Gujarat, India with offices in Jersey City, New Jersey, Sydney, Australia, Jundiaí, Brazil, and Hong Kong. Founded in 2008, the company employs 51-200 professionals. Legal entity: Prismetric Technologies Private Limited. The company maintains positive reviews on Clutch with clients praising quality work, competitive pricing, and communication, having delivered over 500 successful product launches across multiple countries with an in-house AI-powered development platform called Vitara.AI that claims to reduce coding by 95% and accelerate development 10x faster.
10. SoftBlues – Build AI Products. Automate Your Business.
SoftBlues is positioned among UK’s Top 10 AI Developers, specializing in implementing powerful AI assistants and seamless AI integrations for startups and enterprises. This JavaScript-focused company with 15 years of experience maintains a narrow focus on the JavaScript ecosystem to create scalable, meaningful hi-tech solutions.
Voice Agent Development Approach:
SoftBlues’ JavaScript ecosystem focus (leveraging React.js, Vue.js, Node.js, and React Native) helps create scalable hi-tech solutions. The team of 40+ highly-skilled Senior-Middle developers brings subject matter expertise with engineering output focused on product delivery. Services include AI voice assistants (inbound), AI voice outbound agents, AI assistant development, and conversational AI services. The company develops dual-channel solutions integrating phone and WhatsApp capabilities for comprehensive customer communication coverage.
Portfolio and Key Customers:
An AI virtual concierge for an aesthetic clinic showcases dual-channel capabilities: an AI receptionist handling both phone and WhatsApp providing 24/7 support, managing inquiries, delivering treatment details, and handling appointments like a professional human receptionist. An AI-powered hair care system for a UK beauty retailer improves customer experience. The dealership AI voice outbound system “Marc” serves Car Avenue, a Mercedes-Benz dealership in Belgium. Client testimonials include Shift, AutoBI (which won a national grant and secured enterprise clients), and Voiijer Inc. With 700+ projects completed across e-commerce, fintech (FinData Analyst), real estate, HR (CV Sense), manufacturing (Knowcore AI), and education (Lumono.ai), SoftBlues demonstrates broad industry reach.
Company Information:
SoftBlues is based in the United Kingdom (specific city not disclosed). Founded around 2010 (15 years of experience as of 2025), the company employs 40+ Senior-Middle developers. Recognition includes Top UK ClutchAI Company status, 5-star rating on Clutch, Google Cloud Premier Partner status, and £1M insurance protection with 10+ years market presence and dozens of award-winning projects.
Making Your Final Decision
Most companies can build voice agent demos. Few have shipped systems that handle production failures—telephony degradation, concurrent load, conversation breakdowns under real user behavior.
Your evaluation reduces to one question: Can this company show they’ve solved problems similar to yours in production? Companies with proven experience recognize production failures immediately and can show monitoring dashboards from live systems. Companies building their first voice agent on your project will spend months learning what experienced teams already know.
Frequently Asked Questions
Not necessarily. Platforms work well for standard use cases with moderate call volumes and basic integrations. Custom development makes sense when voice is a strategic differentiator, conversations are complex, or compliance and scale are critical.
Sub-500 milliseconds is ideal. Anything slower can feel laggy to users, even if it would be fine for a text chatbot. Low latency requires careful coordination between speech-to-text, reasoning, and text-to-speech components.
Yes, but only if the system is designed for it. Good voice agents include robust speech recognition, error handling, and conversation repair strategies to manage accents, overlapping speakers, and noisy environments.
Run a proof of concept (POC) testing your specific technical challenges over 2–4 weeks. Focus on your hardest problems: latency under concurrent calls, integration with your actual systems, and conversation quality with real user scenarios.
Check their experience with production voice agents, industry knowledge, technical capabilities, and references. Ask about real metrics like completion rates, escalations, and latency. Communication quality and total cost of ownership are just as important as technical skills.
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