Robots can communicate with customers through various methods, depending on the robot's design and intended purpose. Here are some common approaches:

• Speech Synthesis:
  Robots can use text-to-speech (TTS) technology to verbally communicate with customers. This involves converting written text into spoken words, allowing the robot to provide information, answer questions, and offer assistance. Advanced systems can incorporate natural language processing (NLP) to understand and respond to spoken commands.
• Display Screens:
  Many robots incorporate display screens to show text, images, videos, or interactive interfaces. These screens can present information, guide users through processes, or display visual feedback during interactions.
• Gestures and Body Language:
  Robots can be programmed to use gestures, such as pointing, waving, or nodding, to convey meaning and enhance communication. Body language can make interactions feel more natural and intuitive.
• Touchscreen Interfaces:
  Touchscreen interfaces allow customers to interact directly with the robot by touching the screen to select options, input information, or navigate menus. This is a common method for self-service kiosks and interactive robots.
• Voice Recognition:
  Robots can use voice recognition technology to understand spoken commands and questions from customers. This enables hands-free interaction and allows customers to communicate naturally.
• Chatbots and Natural Language Processing:
  Integrating chatbot technology and NLP enables robots to understand and respond to natural language input from customers. This allows for more conversational and intuitive interactions.
• Projections:
  Some robots use projections to display information or create interactive interfaces on nearby surfaces. This can provide a larger and more immersive display than a traditional screen.
• Mobile Apps:
  Robots can communicate with customers through dedicated mobile apps, allowing them to control the robot, receive updates, or access additional features and information.

The best method depends on the use case. For example, a customer service robot in a store might use a combination of speech, a display screen, and gestures to interact with customers, while a delivery robot might primarily use text messages or a mobile app to communicate delivery status.

For more information, you might find the following resources helpful:

• Oracle Chatbot design
• Robotic Interaction: Communication between Human and Robot