Voice assistant modules are small ready-made circuit boards that contain the microphones, sound processing and software that a device needs to understand spoken commands. A device maker builds one into its own smart speaker, soundbar or appliance, instead of designing all of this itself. The voice assistant itself is software, run by a large technology company, that answers questions and controls devices in the home.
Building voice control from the start is hard. The device must hear a person across a noisy room, even while it is playing music itself. It must react only to its wake word, such as the assistant's name, and not to every conversation. It must connect to Wi-Fi and to the assistant's cloud servers. And it usually has to pass the assistant company's certification tests before it can be sold with that assistant. A module arrives with these problems already solved.
A typical module carries two to six microphones, a Wi-Fi and Bluetooth chip, a processor for sound, memory and the software. The software first cleans the sound. Echo cancellation removes the device's own music from what the microphones hear. Beamforming compares the moments at which a sound reaches each microphone, to work out which direction the voice is coming from and pick it out from the noise. Then a small program on the module listens only for the wake word. Only after it hears the wake word does the module send the request to the cloud. There, speech recognition turns the speech into text, and the assistant works out what to do.
Say an Indian audio company in Gurugram wants to add a voice assistant to its new soundbar. Its engineers are experts in speakers and amplifiers, not in microphones and cloud software. They buy a voice module, design the soundbar's main board around it, and connect the module's audio output to their own amplifier. The module's maker helps them pass the assistant's certification. The soundbar can reach shops in months rather than years. A buyer can then say "turn on the living-room lights", and the assistant sends the command to the cloud of the smart lighting maker.
Most voice assistants today send the recorded speech to the cloud, as described in IoT architecture. Newer designs answer faster. Real-time voice AI models respond almost as quickly as a person does. Some small models can run on the device itself, so that simple commands work even when the internet is down.
A voice assistant module is different from the chip inside it. A chip maker sells a bare chip, and the device maker must design everything around it. A module maker sells a finished, tested board, with the chip, the microphones and the software already working together.