What Is the ROI of a Speech-to-Speech AI Solution vs. IVR?

Performance Comparison: Engagement & Resolution

What This Table Shows

This table compares key performance indicators (KPIs) between:

• Speech-to-Speech (S2S) AI: Advanced AI that understands and responds naturally to voice in real time.

• Speech-to-Text (S2T) AI / IVR: Traditional voice systems that transcribe speech into text and route based on rigid rules.

Each KPI directly impacts customer experience, operational efficiency, and cost-to-serve. Let’s go line by line:

1. CSAT (Customer Satisfaction)

• S2S AI: ✅ 80–90%

• S2T IVR: ⚠️ 60–70%

• Source: Forrester, NICE CX Index

Explanation:
Customers rate their satisfaction significantly higher with S2S AI because conversations feel natural, fast, and more empathetic. Traditional IVRs frustrate users with menus, delays, and lack of understanding, dragging CSAT down.

Impact: Higher CSAT correlates with lower churn, better retention, and higher customer lifetime value (CLTV).

2. Containment Rate

• S2S AI: ✅ Up to 85%

• S2T IVR: ⚠️ 30–40%

• Source: Cognigy, IBM, Deloitte

Explanation:
This refers to how often calls are resolved without needing a live agent. S2S AI can handle complex queries on the spot—thanks to conversational intelligence—while IVRs can’t answer follow-up questions or adapt in real-time.

Impact: Higher containment = fewer agent escalations, reduced cost-per-call, and lower staffing needs.

3. First Contact Resolution (FCR)

• S2S AI: ✅ 85–90%

• S2T IVR: ⚠️ ~60–70%

• Source: Contact Babel, Verint

Explanation:
FCR measures how often a customer gets their issue solved on the first call. S2S AI can access backend systems, clarify needs instantly, and take action—unlike rigid IVRs that often pass customers around.

Impact: Better FCR = higher productivity, reduced repeat calls, and happier customers.

4. Net Promoter Score (NPS)

• S2S AI: ✅ +20 to +40 point lift

• S2T IVR: ⚠️ Neutral impact

• Source: Genesys, Gartner

Explanation:
NPS reflects how likely a customer is to recommend your brand. S2S AI lifts NPS by making service feel premium, easy, and efficient. IVR often leaves a neutral or even negative impression.

Impact: High NPS = increased referrals, positive brand equity, and organic growth.

5. Average Handle Time (AHT)

• S2S AI: ✅ 20–30% faster

• S2T IVR: ⚠️ No direct reduction

• Source: Twilio, LivePerson

Explanation:
S2S AI understands intent faster and can resolve issues directly, shortening conversations. IVR systems, with menus and transfers, often waste time.

Impact: Shorter AHT = lower cost per interaction and higher throughput for your team.

6. Abandonment Rate (IVR/Voice)

• S2S AI: ✅ 10–12%

• S2T IVR: ⚠️ 20–25%

• Source: McKinsey, NICE CXone

Explanation:
This is the % of callers who hang up before getting help. S2S AI engages instantly and feels intuitive, keeping users on the line. IVR’s complexity and delays cause people to quit the call.

Impact: Lower abandonment = higher resolution rates, less lost revenue, and fewer missed opportunities.

7. Agent Workload Reduction

• S2S AI: ✅ High

• S2T IVR: ⚠️ Low

• Source: Cognigy, NICE

Explanation:
S2S AI reduces the number of contacts agents need to handle—by automating complete resolutions or handling the heavy lifting. IVR often just triages calls, pushing the burden back to humans.

Impact: High automation = smaller or more scalable agent teams, cost savings, and more focus on complex, high-value cases.

Speech-to-Speech AI vs. Chatbots: KPI Deep Dive

1. Containment Rate

• Chatbots: 40–60%

• Speech-to-Speech AI: ✅ 70–85%

• Source: Deloitte, McKinsey

Explanation:
Containment refers to how well the system can resolve customer queries without escalation to a human agent.

• Chatbots are often limited to scripted flows and can't handle unstructured or voice-first issues well.

• S2S AI handles voice queries naturally, with contextual understanding, leading to significantly better resolution rates.

Impact: Higher containment means fewer calls to agents = lower cost-to-serve and greater scalability.

2. CSAT (Customer Satisfaction)

• Chatbots: 65–75%

• Speech-to-Speech AI: ✅ 80–90%

Explanation:
Customers typically find chatbots "helpful but robotic." They expect more when speaking. S2S AI mimics human interaction—responding conversationally, empathetically, and in real time.

Impact: Higher CSAT leads to higher retention, lower churn, and better brand perception.

3. NPS (Net Promoter Score)

• Chatbots: Neutral or slight positive

• Speech-to-Speech AI: ✅ +20 to +40 points

• Source: NICE CXone

Explanation:
While chatbots may satisfy, they rarely "wow" customers. S2S AI can delight users by providing immediate, frictionless support that feels like a real human is helping.

Impact: Higher NPS = more referrals, brand loyalty, and long-term value growth.

4. Engagement Rate

• Chatbots: ~40–50%

• Speech-to-Speech AI: ✅ 60–75%

• Source: LivePerson, CallMiner

Explanation:
This is the % of users who actively engage with the solution. Many users skip or bypass bots because of poor UX. S2S AI engages users the moment they speak, in a format that feels personal and natural.

Impact: Better engagement = higher resolution volumes, more data captured, and better customer journeys.

5. First Contact Resolution (FCR)

• Chatbots: 60–70%

• Speech-to-Speech AI: ✅ 85–90%

Explanation:
Chatbots often resolve only basic queries. S2S AI, with voice input, can clarify user intent and resolve complex requests directly—often without follow-up.

Impact: Higher FCR reduces repeat contacts, customer frustration, and support costs.

6. Average Handle Time (AHT)

• Chatbots: Better than humans

• Speech-to-Speech AI: ✅ 15–30% faster than bots

• Source: Contact Babel

Explanation:
While bots are faster than humans, S2S AI is even faster—because it skips typing, reading, and navigating menus. It processes intent and acts in real time, reducing total time to resolution.

Impact: Faster handling = lower costs, more throughput, and shorter wait times.

7. Abandonment Rate

• Chatbots: ~20%

• Speech-to-Speech AI: ✅ 10–12%

• Source: NICE

Explanation:
Users often abandon bots when they feel stuck or when typing becomes too slow or awkward. Voice-first systems with natural interaction drastically reduce drop-offs.

Impact: Lower abandonment = more conversions, better CX, and less lost revenue.

8. Multilingual Support

• Chatbots: Manual setup per language

• Speech-to-Speech AI: ✅ Built-in real-time translation

• Source: Deepgram

Explanation:
Chatbots usually require separate flows for each language, needing extensive maintenance. S2S AI can auto-detect language and provide multilingual support instantly.

Impact: Built-in multilingual capabilities = broader global reach with lower operational complexity.

9. Emotional Personalisation

• Chatbots: ❌ None

• Speech-to-Speech AI: ✅ Yes—empathetic tone & reactions

• Source: Kore.ai, Cognigy

Explanation:
Chatbots are text-based and flat-toned. S2S AI can recognise emotions (e.g., frustration, urgency) from vocal signals and adjust tone or pace accordingly—providing more humanised experiences.

Impact: Emotional intelligence = stronger customer trust, better outcomes, and higher satisfaction.

What Does That Mean for ROI?

If you handle 1,000 calls/month, here’s what you could unlock:

Purpose of the Table

This table translates the operational improvements of S2S AI into direct monthly and annual financial value, based on a scenario of 1,000 inbound calls per month. These values come from actual calculations (via your ROI Excel model) and use conservative estimates for uplift and cost savings.

Assumptions (implied or editable in your calculator):

• £4 saved per call that is deflected/resolved without an agent

• £2 gained for each call not abandoned

• Agent time valued at £0.50 per minute

• Simply AI’s monthly cost: £200

• Results are scalable—double the calls, double the savings.

1. Containment Rate Uplift – £2,000/month

500 calls x £4 saving per call

Explanation:
S2S AI can contain (resolve) more calls compared to IVR. With a containment uplift of ~50% (on top of IVR’s baseline), 500 more calls per month are resolved without agent involvement.

Value to CFO:

• Saves £4 per agent-handled call avoided

• Annual savings: £24,000

2. First Contact Resolution Uplift – £900/month

225 calls x £4 saved per call

Explanation:
By increasing the likelihood of resolving an issue on the first try (without callbacks or escalations), S2S AI reduces the total number of interactions needed per resolution.

Value to CFO:

• Avoids repeat contacts

• Improves agent productivity

• Annual savings: £10,800

3. Reduced Abandonment Rate – £230/month

115 extra completed calls x £2 value per call

Explanation:
S2S AI lowers the number of customers who hang up before being helped (from ~25% down to 10–12%). Each saved call might represent a converted sale, retention event, or brand touchpoint.

Value to CFO:

• Revenue not lost to drop-offs

• Better customer experience

• Annual value protected: £2,760

4. Agent Workload Reduction – £600/month

150 fewer agent calls x £4 saved per call

Explanation:
By resolving more calls with automation, S2S AI reduces the number of interactions that reach live agents—cutting staffing needs or freeing agents for higher-value work.

Value to CFO:

• Cuts cost per call

• Boosts team utilization

• Annual efficiency gain: £7,200

5. Customer Retention (CSAT/NPS Uplift) – £400/month

2% retention lift on £20,000 monthly customer value

Explanation:
Higher CSAT and NPS from S2S AI means more customers stay loyal and continue purchasing. This estimates a 2% reduction in churn across customers worth £20K/month.

Value to CFO:

• Protects revenue base

• Drives LTV increase

• Annual retention ROI: £4,800

6. Average Handle Time (AHT) Savings – £100/month

200 minutes saved x £0.50/min

Explanation:
By reducing the time spent per call (via better understanding, quicker action), S2S AI saves agent minutes. At a conservative 200 minutes/month, this adds up quickly.

Value to CFO:

• Time is money—literally

• Helps avoid new hires during scale

• Annual cost efficiency: £1,200

What This Means:

• For every £1 you spend, you’re generating £21 in business value.

• With a fixed monthly cost, the ROI scales linearly with call volume.

• Profitability increases over time as the AI learns and improves performance.

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