AI Voice Interviews Outperform Human Recruiters: 2025 Research Analysis

Game-Changing Research: AI Interviews Beat Human Recruiters

A groundbreaking field study published in August 2025 has turned conventional recruitment wisdom on its head. The research, "Voice AI in Firms: A Natural Field Experiment on Automated Job Interviews" by economists Brian Jabarian (University of Chicago Booth) and Luca Henkel (Erasmus University Rotterdam), analyzed over 70,000 job applications to determine whether artificial intelligence can effectively conduct job interviews.

📊 Download the Full Research Paper (PDF) | View on SSRN

The results? AI not only matched human performance but significantly outperformed traditional recruiters across multiple key metrics.

Key Research Findings: The Numbers That Matter for Recruiters

Dramatic Improvements in Hiring Outcomes

The study revealed remarkable improvements when AI voice agents conducted interviews compared to human recruiters:

• 12% increase in job offers extended to candidates

• 18% increase in job starts (candidates actually showing up for work)

• 17% improvement in 30-day retention rates

• 24% more hiring-relevant topics covered in AI-led interviews (6.8 topics vs. 5.5)

These aren't marginal gains—they represent substantial improvements that directly impact a company's bottom line through reduced time-to-hire, lower recruitment costs, and improved quality of hire. Learn more about how AI is transforming recruitment metrics.

AI interviews significantly improve hiring outcomes across all stages.

The Candidate Preference: 78% Choose AI Over Humans

Perhaps most surprising was candidate behavior when given a choice. When applicants could select between human and AI interviewers, an overwhelming 78% opted for the AI-led interview.

Why did candidates prefer AI interviews?

• Convenience and flexibility in scheduling

• Reduced anxiety from talking to a non-judgmental system

• Consistency in questioning and evaluation

• No perceived bias or personal judgment during the conversation

The research also revealed that candidates with lower standardized test scores were more likely to choose AI interviews, suggesting these systems may help level the playing field for applicants who interview poorly due to anxiety or social factors rather than actual job capability.

How the Study Was Conducted: Real-World Field Experiment

This wasn't a laboratory simulation—it was a large-scale natural field experiment conducted with PSG Global Solutions, a major recruitment firm, for entry-level customer service positions in the Philippines.

Experimental Design

Applicants were randomly assigned to one of three groups:

1. AI Interview Group: Interviewed by "Anna AI," PSG's proprietary voice agent

2. Human Interview Group: Interviewed by experienced human recruiters

3. Choice Group: Given the option to select between AI or human interviewer

Critically, all interview questions remained standardized across groups, and final hiring decisions were always made by human recruiters who reviewed:

• Interview transcripts

• Call recordings

• Standardized test scores

This design ensured that any differences in outcomes resulted from the interview process itself, not from differences in final decision-making.

Why AI Interviews Perform Better: Three Critical Mechanisms

The research identified three key reasons why AI-led interviews produced superior results:

1. More Comprehensive Information Gathering

AI interviewers extracted significantly more hiring-relevant information from candidates. Transcript analysis showed AI covered an average of 6.8 relevant topics per interview compared to just 5.5 topics in human-led interviews—a 24% improvement.

Why does this happen?

• AI consistently follows structured interview protocols without deviation

• No conversational tangents or off-topic discussions

• Better time management throughout the interview

• Systematic probing of all relevant competency areas

2. Higher Performance Ratings from Recruiters

When human recruiters evaluated interview transcripts, they consistently rated candidates from AI-led interviews higher on key performance dimensions. This suggests AI interviews help candidates present themselves more effectively.

Interestingly, recruiters also placed greater weight on standardized test scores when evaluating AI-interviewed candidates, possibly trusting the systematic nature of AI-conducted interviews more than human ones.

This higher quality assessment translates into real-world outcomes. Among candidates who accepted job offers, those interviewed by AI showed significantly better follow-through and retention:

Figure 3: Quality improvements persist through the hiring funnel.

3. Maintained Candidate Experience Quality

Despite initial concerns from professional recruiters that AI would harm candidate experience, applicants rated both AI and human interviewers similarly on:

• Overall interview quality

• Recruiter professionalism

• Communication clarity

• Satisfaction with the hiring process

Customer experience surveys showed no significant difference in satisfaction scores between interview types.

The Challenges: Technical Issues and Limitations

While the results were overwhelmingly positive, the study also documented important challenges with AI interview systems:

Technical Difficulties

• 5% of applicants discontinued AI interviews before completion

• 7% experienced technical glitches that added stress to the process

• Some candidates struggled with the technology interface

• Audio quality issues occasionally impacted conversation flow

Important Context

The study focused exclusively on entry-level customer service roles with standardized requirements. Results may vary for:

• Senior-level positions requiring nuanced assessment

• Roles with complex technical requirements

• Positions where cultural fit is paramount

• Industries with specialized hiring needs

What This Means for Modern Recruitment: Practical Implications

For Recruiting Teams

This research provides strong evidence that AI interview technology should be seriously considered for:

1. High-volume recruitment: Screening large applicant pools efficiently

2. Entry to mid-level positions: Where standardized competencies can be assessed

3. Initial screening stages: Qualifying candidates before human interviews

4. 24/7 interview availability: Accommodating candidates across time zones

5. Consistency in evaluation: Reducing interviewer bias and variability

The data confirms what forward-thinking teams already know: AI recruiters can match or exceed human performance while dramatically improving efficiency.

For Hiring Managers

The findings suggest several strategic considerations:

• Rethink interview protocols: AI demonstrates that structured interviews work better

• Combine AI with human judgment: Use AI for initial screening, humans for final decisions

• Focus human time on high-value activities: Let AI handle routine screening (recruiters currently spend 80% of their time on administrative tasks)

• Measure quality of hire: Track whether AI-interviewed hires perform better long-term

• Consider candidate preferences: Many applicants actively prefer AI interviews

For Talent Acquisition Technology

Companies like shortlistd.io, which has pivoted to focus on autonomous hiring intelligence, should consider how AI interview capabilities integrate with existing:

• Applicant tracking systems (ATS)

• Candidate relationship management (CRM) platforms

• Assessment and testing tools

• Video interview platforms

• Recruitment analytics dashboards

The Future of AI in Recruitment: Beyond Interviews

This research represents just one application of artificial intelligence in talent acquisition. The broader implications extend to:

Emerging AI Applications in Hiring

• Resume screening automation: AI parsing thousands of applications in minutes

• Predictive analytics: Identifying candidates most likely to succeed

• Bias detection: Algorithmic fairness in hiring decisions

• Candidate matching: AI-powered job-candidate fit scoring

• Interview question generation: Dynamic, role-specific questioning

• Reference checking automation: AI-conducted reference interviews

• Onboarding optimization: Personalized new hire experiences

Ethical Considerations and Best Practices

As AI becomes more prevalent in recruitment, organizations must address:

• Transparency: Informing candidates about AI usage in hiring

• Data privacy: Protecting candidate information and interview recordings

• Algorithmic bias: Regular auditing to ensure fair treatment

• Human oversight: Maintaining human decision-making for final offers

• Regulatory compliance: Adhering to employment law and AI regulations

• Candidate recourse: Providing options to appeal AI-driven decisions

Expert Perspectives: What Industry Leaders Are Saying

The research has generated significant attention across the recruitment industry. As noted by talent acquisition experts, this study provides the first large-scale empirical evidence that AI can not only match but exceed human performance in conducting job interviews.

The Financial Times, Fortune, and major HR publications have covered the findings, signaling growing mainstream acceptance of AI recruitment technologies.

Dr. Brian Jabarian, the study's lead author and economist at University of Chicago Booth School of Business, emphasized: "What we found from data in our large-scale study was that Anna AI can match human recruiters in conducting job interviews—a complex but key task in hiring—while preserving candidate satisfaction, maintaining smooth operations, and improving hiring efficiency and early retention."

Implementing AI Interviews: A Strategic Roadmap

Ready to integrate AI interview technology into your recruitment process? Here's your step-by-step guide to building an AI recruiting workforce.

Phase 1: Assessment (Weeks 1-4)

• Evaluate current interview processes and pain points

• Identify high-volume roles suitable for AI screening

• Research AI interview vendors and capabilities

• Calculate potential ROI and cost savings

• Assess legal and compliance requirements

Phase 2: Pilot Program (Weeks 5-12)

• Select one or two roles for initial testing

• Configure AI interview questions and evaluation criteria

• Train recruiting team on the new system

• Run parallel process: both AI and human interviews

• Collect data and candidate feedback

Phase 3: Optimization (Weeks 13-20)

• Analyze pilot results and quality of hire data

• Refine interview scripts and evaluation models

• Address technical issues and candidate concerns

• Develop standard operating procedures

• Create training materials for broader rollout

Phase 4: Scaling (Weeks 21+)

• Expand to additional roles and departments

• Integrate with existing recruitment technology stack

• Establish ongoing monitoring and optimization

• Continuously measure impact on hiring outcomes

• Share best practices across the organization

Measuring Success: Key Performance Indicators

To evaluate AI interview effectiveness, track these critical metrics:

Efficiency Metrics

• Time-to-interview (days from application to interview)

• Time-to-hire (days from application to offer acceptance)

• Recruiter hours saved per hire

• Interview completion rates

• Cost-per-hire reduction

Quality Metrics

• Offer acceptance rate

• New hire 30-day retention rate

• New hire 90-day performance ratings

• Hiring manager satisfaction scores

• Candidate experience survey results

Equity Metrics

• Demographic diversity of interviewees

• Pass-through rates by candidate demographics

• Adverse impact analysis

• Candidate complaints or concerns

• Fairness audit results

The Competitive Advantage: Why Early Adopters Win

Organizations that embrace AI interview technology now position themselves for significant advantages:

Talent Market Benefits

• Faster response times attract top candidates who are interviewing elsewhere

• Better candidate experience improves employer brand and reputation

• Wider talent pools through 24/7 interview availability

• Reduced bias creates more diverse and inclusive teams

• Data-driven insights continuously improve hiring outcomes

Operational Benefits

• Scale without proportional cost increases (potentially saving 60%+ on traditional recruitment agency fees)

• Redeploy recruiters to strategic activities like candidate relationships

• Consistent evaluation standards across all interviews

• Better documentation for compliance and improvement

• Predictive analytics on candidate success factors

Common Objections and Concerns Addressed

"Candidates won't accept AI interviews"

The research directly contradicts this concern—78% of candidates chose AI when given the option. Modern candidates, especially younger generations, are comfortable with AI interactions and often prefer the convenience.

"AI can't assess soft skills and cultural fit"

While AI excels at structured competency assessment, human judgment remains crucial for nuanced evaluation. The optimal approach combines AI screening with human interviews for advanced stages.

"It's too expensive to implement"

The cost-benefit analysis strongly favors AI interviews for high-volume roles. The 12-18% improvement in hiring outcomes, combined with time savings, typically provides ROI within 6-12 months.

"We'll lose the human touch in recruitment"

AI doesn't replace human recruiters—it augments them. By handling routine screening, AI frees recruiters to focus on relationship-building, candidate coaching, and strategic talent planning.

"Our industry is different"

While this specific study focused on customer service roles, the principles of structured interviews and consistent evaluation apply across industries. Many organizations already successfully use AI interviews in healthcare, retail, technology, finance, and other sectors.

The Research That Changes Everything

This 2025 field study by Jabarian and Henkel represents a watershed moment for recruitment technology. For the first time, large-scale empirical evidence demonstrates that AI voice interviews not only work but actively improve hiring outcomes across multiple dimensions.

For recruitment platforms like shortlistd.io and forward-thinking talent acquisition teams, the message is clear: AI interview technology is no longer experimental—it's a proven tool that delivers measurable improvements in efficiency, quality, and candidate experience.

The question is no longer whether to adopt AI interviews, but how quickly your organization can implement them to gain competitive advantage in the war for talent.

Key Takeaways for Recruitment Professionals

1. AI interviews increase job offers by 12% and retention by 17% compared to human-led interviews

2. 78% of candidates prefer AI interviews when given the choice

3. AI extracts 24% more hiring-relevant information from candidates

4. Candidate satisfaction remains high with AI interview experiences

5. Best results come from hybrid approaches combining AI screening with human decision-making

6. Early adopters gain significant competitive advantages in talent acquisition

7. Technical challenges exist but are manageable with proper implementation

8. ROI is measurable and significant for high-volume recruitment

About This Research

Study Title: Voice AI in Firms: A Natural Field Experiment on Automated Job Interviews

Authors: Brian Jabarian (University of Chicago Booth School of Business) and Luca Henkel (Erasmus University Rotterdam)

Publication Date: August 18, 2025

Sample Size: 70,884 job applications across 48 job postings

Awards:

• NABE E. A. Mannis Prize (2025)

• Thaler-Tversky Award (2025)

Pre-registration: AEA RCT Registry #15385

Related Topics and Resources

Explore More on shortlistd.io:

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• 50+ AI Recruiting Statistics That Will Transform Your Hiring - Comprehensive data on the AI recruiting revolution

• AI Recruiters vs Human Recruiters: Who Wins in 2025? - Detailed comparison of AI and human performance

• The End of Expensive Recruitment Agency Fees - How AI delivers 60% cost savings

Implementation Guides

• Your Step-by-Step Guide to Building an AI Recruiting Workforce - Complete implementation roadmap

• The Shocking Truth About How Recruiters Spend Their Time - Why automation is essential

Company Vision

• Why We're Pivoting to Autonomous Hiring Intelligence - Our journey and vision

• How Two Experts Saw the Future of Recruitment Coming - The story behind shortlistd.io

Research References

• Download Full Research Paper (PDF) - "Voice AI in Firms: A Natural Field Experiment on Automated Job Interviews"

• View on SSRN - Official research repository

• Brian Jabarian's Research Profile - Lead researcher's website

Additional Topics

• AI recruiting software comparison

• Automated candidate screening best practices

• Recruitment automation ROI calculator

• Interview bias reduction strategies

• Candidate experience optimization

• Hiring efficiency metrics and benchmarks

• Applicant tracking system integration

• Voice AI technology in HR

• Future of talent acquisition

• Recruitment technology trends 2025

This analysis was created by shortlistd.io to help recruitment professionals understand and implement cutting-edge hiring technology. shortlistd.io provides AI-powered autonomous hiring intelligence that transforms recruitment with always-on candidate engagement, automated screening, and intelligent interview technology. For more insights on AI-powered candidate screening and recruitment automation, explore our platform or read about how our founders saw the future of recruitment coming.