Customer Input Handling

The Switchboard framework provides powerful, flexible APIs for collecting customer input through both speech recognition (ASR) and DTMF (keypad) input.

Overview

The framework supports three main approaches to customer input:

Simple DTMF Input - Basic keypad input collection
Unified Input Routing - Route based on both speech intents and DTMF digits
Sequential Input Mode - Attempt speech recognition first, with automatic fallback to DTMF

Simple DTMF Input

For basic keypad input collection, use the GetCustomerInput method:

csharp

var flow = new FlowBuilder()
    .SetName("BasicInput")
    .GetCustomerInput(
        promptText: "Press 1 for sales, 2 for support",
        branches: input => input
            .OnDigit("1", sales => sales
                .PlayPrompt("Connecting to sales...")
                .TransferToQueue("Sales")
                .Disconnect())
            .OnDigit("2", support => support
                .PlayPrompt("Connecting to support...")
                .TransferToQueue("Support")
                .Disconnect())
            .OnTimeout(timeout => timeout
                .PlayPrompt("We didn't receive your input")
                .Disconnect())
            .OnError(error => error
                .PlayPrompt("An error occurred")
                .Disconnect())
            .OnDefault(def => def
                .PlayPrompt("Invalid selection")
                .Disconnect()),
        configure: action =>
        {
            action.MaxDigits = 1;
            action.TimeoutSeconds = 5;
        },
        identifier: "basic-input")
    .Build();

Why use the branches: overload?

The branches: overload returns the parent IFlowBuilder, which makes it easier to compose flows where you want to keep chaining after you finish defining the input branches.

Unified Input Routing

The RouteByInput API allows you to handle both speech intents and DTMF digits with a single routing configuration:

Basic Routing

csharp

.RouteByInput(router => router
    .WhenIntent("sales_intent", sales => sales
        .PlayPrompt("Routing to sales team")
        .TransferToQueue("Sales"))
    .WhenDigits(["1", "2" ], sales => sales
        .PlayPrompt("Routing to sales via DTMF")
        .TransferToQueue("Sales"))
    .Otherwise(other => other
        .PlayPrompt("I didn't understand that")
        .Disconnect())
)

Unified Routes (Same Destination)

For cases where you want speech and DTMF to route to the same destination:

csharp

.RouteByInput(router => router
    // Unified route - both intent and digits go to same flow
    .When("sales_intent", ["1","2"], sales => sales
        .PlayPrompt("Connecting to sales")
        .TransferToQueue("Sales"))

    .When("support_intent", ["3", "4" ], support => support
        .PlayPrompt("Connecting to support")
        .TransferToQueue("Support"))

    // Fallback for unrecognized input
    .Otherwise(other => other
        .PlayPrompt("I didn't catch that, let me transfer you to an agent")
        .TransferToQueue("GeneralSupport"))
)

Complex Multi-Route Example

csharp

.RouteByInput(router => router
    // VIP customers
    .When("vip_intent", ["9"], vip => vip
        .PlayPrompt("Welcome VIP customer! Connecting to our premium support team")
        .TransferToQueue("VIPSupport"))

    // Sales department
    .WhenIntent("sales_intent", sales => sales
        .SetContactAttributes(attrs => attrs["Department"] = "Sales")
        .TransferToQueue("Sales"))

    .WhenDigits(["1", "2" ], sales => sales
        .SetContactAttributes(attrs => attrs["Department"] = "Sales")
        .PlayPrompt("You pressed for sales")
        .TransferToQueue("Sales"))

    // Technical support
    .When("tech_support_intent", new[] { "3" }, tech => tech
        .PlayPrompt("Connecting to technical support")
        .TransferToQueue("TechSupport"))

    // Billing
    .WhenDigits(["4", "5"], billing => billing
        .TransferToQueue("Billing"))

    // Default/unrecognized
    .Otherwise(other => other
        .PlayPrompt("I'm not sure what you need. Let me connect you with someone who can help")
        .TransferToQueue("GeneralSupport"))
)

Sequential Input Mode (ASR → DTMF Fallback)

Sequential mode attempts speech recognition first, then automatically falls back to DTMF input based on configurable triggers.

Basic Sequential Configuration

csharp

.GetCustomerInput(input =>
{
    // Primary mode: Try speech first
    input.Primary.Mode = InputMode.Speech;
    input.Primary.LexBot = "CustomerServiceBot";
    input.Primary.LexBotAlias = "Production";
    input.Primary.Prompt = "How can I help you today? Say sales, support, or billing.";
    input.Primary.ConfidenceThreshold = 0.7; // Only accept matches >= 70% confidence
    input.Primary.MaxRetries = 2;

    // Fallback mode: Use DTMF if speech fails
    input.Fallback.Mode = InputMode.DTMF;
    input.Fallback.PromptText = "I didn't catch that. Please use your keypad. Press 1 for sales, 2 for support, 3 for billing.";
    input.Fallback.MaxDigits = 1;

    // Control when to fallback
    input.FallbackTriggers = FallbackTrigger.NoMatch | FallbackTrigger.LowConfidence | FallbackTrigger.Timeout;
    input.EnableFallback = true;
})

Fallback Triggers

The FallbackTrigger enum controls when the system should fallback from speech to DTMF:

csharp

// Individual triggers
FallbackTrigger.Timeout           // Customer didn't say anything
FallbackTrigger.NoMatch           // Speech not recognized
FallbackTrigger.LowConfidence     // Confidence below threshold
FallbackTrigger.InvalidInput      // Input doesn't match expected format
FallbackTrigger.Error             // System error during recognition
FallbackTrigger.MaxRetriesExceeded // Customer exceeded retry attempts

// Combined triggers (use bitwise OR)
input.FallbackTriggers = FallbackTrigger.Timeout | FallbackTrigger.NoMatch;

// Predefined combinations
FallbackTrigger.AnyError          // All error conditions (excludes MaxRetriesExceeded)
FallbackTrigger.All               // Everything (including MaxRetriesExceeded)

Advanced Sequential Example

csharp

.GetCustomerInput(input =>
{
    // ===== PRIMARY: Speech Recognition =====
    input.Primary.Mode = InputMode.Speech;
    input.Primary.LexBot = "MultiLanguageBot";
    input.Primary.LexBotAlias = "Production";
    input.Primary.LexBotVersion = "V2";
    input.Primary.Locale = "en_US";

    // Initial prompt
    input.Primary.Prompt = "Welcome! How may I assist you today?";

    // Retry prompt (if customer not understood)
    input.Primary.RetryPrompt = "I'm sorry, I didn't quite catch that. Could you please repeat?";

    // Confidence and retry settings
    input.Primary.ConfidenceThreshold = 0.75; // 75% confidence required
    input.Primary.MaxRetries = 3;             // Try up to 3 times
    input.Primary.TimeoutSeconds = 5;         // 5 seconds to respond

    // Security: Encrypt sensitive input (PCI compliance)
    input.Primary.EncryptInput = false; // Set true for payment card data

    // ===== FALLBACK: DTMF =====
    input.Fallback.Mode = InputMode.DTMF;

    // Fallback prompt explains keypad options
    input.Fallback.PromptText = @"
        I'm having trouble understanding. Let's try the keypad instead.
        Press 1 for sales
        Press 2 for technical support
        Press 3 for billing
        Press 4 for general inquiries
    ";

    // Fallback retry prompt
    input.Fallback.RetryPrompt = "That wasn't a valid selection. Please press 1, 2, 3, or 4.";

    // DTMF settings
    input.Fallback.MaxDigits = 1;
    input.Fallback.MinDigits = 1;
    input.Fallback.TerminatingDigit = "#";  // Optional: press # to submit
    input.Fallback.TimeoutSeconds = 10;     // 10 seconds to enter digit
    input.Fallback.InterDigitTimeoutSeconds = 3; // 3 seconds between digits
    input.Fallback.MaxRetries = 2;

    // ===== FALLBACK TRIGGERS =====
    // Fallback on timeout, no match, or low confidence
    input.FallbackTriggers = FallbackTrigger.Timeout |
                            FallbackTrigger.NoMatch |
                            FallbackTrigger.LowConfidence;

    // Enable automatic fallback
    input.EnableFallback = true;
})
.OnDigit("1", sales => { /* Sales flow */ })
.OnDigit("2", support => { /* Support flow */ })
.OnDigit("3", billing => { /* Billing flow */ })
.OnDigit("4", general => { /* General flow */ })
.OnTimeout(timeout => timeout.Disconnect())

Multi-Language Sequential Input

csharp

.GetCustomerInput(input =>
{
    // Spanish language bot
    input.Primary.LexBot = "CustomerServiceBot_Spanish";
    input.Primary.Locale = "es_US";
    input.Primary.Prompt = "¿Cómo puedo ayudarte hoy?";
    input.Primary.RetryPrompt = "Lo siento, no entendí. ¿Podrías repetir?";

    // Spanish DTMF fallback
    input.Fallback.PromptText = @"
        Usemos el teclado.
        Presiona 1 para ventas
        Presiona 2 para soporte técnico
        Presiona 3 para facturación
    ";
})

Best Practices

When to Use Each Approach

Simple DTMF Input:

Simple menu systems (1-5 options)
Sensitive data collection (SSN, account numbers)
Environments with poor audio quality
When speech recognition is not required

Unified Input Routing:

Modern IVR systems with speech and DTMF options
User preference flexibility
Accessibility requirements
Multi-channel support

Sequential Mode:

Best user experience (try speech first)
Fallback safety net for speech failures
Compliance requirements (must support DTMF for accessibility)
High-quality speech recognition with DTMF backup

Security Considerations

csharp

// For PCI compliance: Encrypt sensitive input
input.Primary.EncryptInput = true;  // Speech
input.Fallback.EncryptInput = true; // DTMF

// Use appropriate timeout for sensitive data
input.Primary.TimeoutSeconds = 30; // Give users time to find their card
input.Fallback.TimeoutSeconds = 30;

Confidence Thresholds

csharp

// High confidence for critical operations
input.Primary.ConfidenceThreshold = 0.85; // 85% for payments, transfers

// Medium confidence for routing
input.Primary.ConfidenceThreshold = 0.70; // 70% for menu navigation

// Lower confidence for informational queries
input.Primary.ConfidenceThreshold = 0.60; // 60% for FAQ, hours

Error Handling

csharp

.RouteByInput(router => router
    .When("cancel_intent", new[] { "*" }, cancel => cancel
        .PlayPrompt("Cancelling. Goodbye!")
        .Disconnect())

    .When("agent_intent", new[] { "0" }, agent => agent
        .PlayPrompt("Connecting to an agent")
        .TransferToQueue("GeneralSupport"))

    // Always provide an "Otherwise" for unrecognized input
    .Otherwise(other => other
        .PlayPrompt("I'm sorry, I didn't understand that")
        .TransferToQueue("GeneralSupport"))
)

Testing Input Flows

csharp

[Test]
public void SequentialInput_WithFallback_ShouldGenerateCorrectFlow()
{
    // Arrange
    var builder = new FlowBuilder();

    // Act
    var flow = builder
        .SetName("TestSequentialInput")
        .GetCustomerInput(input =>
        {
            input.Primary.Mode = InputMode.Speech;
            input.Primary.LexBot = "TestBot";
            input.Fallback.Mode = InputMode.DTMF;
            input.FallbackTriggers = FallbackTrigger.AnyError;
        })
        .OnDigit("1", sales => sales.TransferToQueue("Sales"))
        .Build();

    // Assert
    flow.Should().NotBeNull();
    var inputConfig = /* extract from flow */;
    inputConfig.IsSequential.Should().BeTrue();
}

Flow Basics - Fundamental flow building concepts
Fluent Builders - Complete builder API reference
PlayPrompt Enhancements - Advanced prompt configuration
API Reference: Configuration - InputConfiguration API details

Customer Input Handling ​

Overview ​

Simple DTMF Input ​

Unified Input Routing ​

Basic Routing ​

Unified Routes (Same Destination) ​

Complex Multi-Route Example ​

Sequential Input Mode (ASR → DTMF Fallback) ​

Basic Sequential Configuration ​

Fallback Triggers ​

Advanced Sequential Example ​

Multi-Language Sequential Input ​

Best Practices ​

When to Use Each Approach ​

Security Considerations ​

Confidence Thresholds ​

Error Handling ​

Testing Input Flows ​

Related Documentation ​

Customer Input Handling

Overview

Simple DTMF Input

Unified Input Routing

Basic Routing

Unified Routes (Same Destination)

Complex Multi-Route Example

Sequential Input Mode (ASR → DTMF Fallback)

Basic Sequential Configuration

Fallback Triggers

Advanced Sequential Example

Multi-Language Sequential Input

Best Practices

When to Use Each Approach

Security Considerations

Confidence Thresholds

Error Handling

Testing Input Flows

Related Documentation