Question: I'm looking for a platform to build custom chatbots with advanced features like voice recognition and text-to-speech capabilities.

If you want a platform to build your own chatbots with more advanced features like voice recognition and text-to-speech, Voiceflow is a good choice. It lets you build, deploy and scale chat and voice AI agents with a range of abilities. You can import data and documents to build a knowledge base, create multistep workflows with a visual drag-and-drop interface and manage data in a centralized repository. It also offers integrations with analytics tools, CRM systems, SMS providers and e-commerce sites, so it's highly customizable.

Another good contender is Speech Studio. This is a speech-focused interface that includes core abilities like speech-to-text and text-to-speech. It's good for use cases like customer service chatbots and voice assistants, with real-time speech processing to help you better engage with customers.

If you want to tap into GPT-4 technology, CustomGPT is worth a look. It can be set up with no programming through website integration or document upload and provides GPT-4 answers that are accurate and resistant to manipulation. It can be deployed in a variety of ways, including website embedding and API integration, so it's flexible for boosting customer service and productivity.

Last, ChatNode offers a full-stack platform for building more advanced AI chatbots. It includes features like live agent handoff, customization, multiple data sources and support for 95 languages. It also integrates with websites and Slack channels, and promises to automate up to 80% of customer support tasks and boost efficiency.