In a world where the Internet of Things (IoT) is forecasted to network more than 29 billion devices by 2030 (Statista), voice-activated smart devices have become essential resources for everything from domestic automation to medicine. Juniper Research estimates that there will be 8.4 billion voice assistants in use by 2024, more than the world population—highlighting the exponential rise of audio-first interfaces.
The secret behind these intelligent assistants is that they can record, interpret, and react to sound signals with more than 95% accuracy in real time even under noisy or dynamic conditions. This is made possible by using high-end mic arrays, real-time DSP processing, low-latency firmware, and instant cloud connectivity.
For businesses looking to develop such equipment, the choice of an Audio Product Design Service is the key to making the end product not only functional but also acoustically optimized, compliant, and ready for the world market.
In this end-to-end product development case study, we document the experience of a successful engagement with a prominent home automation company. The product? A small-sized, AI-driven smart speaker with IoT features built in, designed with a keen emphasis on voice command accuracy (97%+), premium music playback, and environmental sound sensitivity for smart automation.
The Challenge
Our consumer electronics client, with a high-growth business, came to us with an attractive vision: to develop a smart home assistant that would deliver fluid voice interaction in noisy settings, along with smart sensors and IoT features for a fully connected home experience.
They required an Audio Product Design Service company that could:
- Design a high-fidelity speaker and microphone system
- Create a noise-immune voice recognition interface
- Optimize battery power consumption
- Gain compliance with large smart assistant platforms (such as Alexa or Google Assistant)
- Enable small form factor and cost-effective manufacturability in volume
Have an audio-first product idea in mind?
Stage 1: Requirements & System Architecture
Before started designing hardware or writing code, our engineering team did a thorough requirement analysis that included:
- Use Case Profiling: Voice commands that work indoors and in rooms
- Audio Performance: 360-degree pickup, voice recognition from far away, and capture within 5m
- Platform Compatibility: Works with Alexa Voice Service and can find local keywords.
- Connectivity: Wi-Fi, BLE, and Zigbee are all ways to connect to the internet and work with smart home devices.
Using this information, we built a modular system that includes:
- An array of digital MEMS microphones
- A low-power DSP for doing pre-processing
- A system-on-chip (SoC) that can connect to Wi-Fi and has Linux-based firmware
- Amplifier Class D with stereo speakerss
Step 2: Microphone Array Design
A 4-mic circular array with integrated beamforming and noise cancellation at its core powered the voice interface of the device.
Important Design Factors:
- MEMS Selection: High SNR (>65 dB), all-around pattern, low power
- Beamforming Algorithm: Supported far-field voice picking up even when playing music
- Echo Cancellation (AEC): Optimized to support speaker output from the same device
- Wake Word Engine: In-house keyword detection engine with <1% false positives
We performed simulations in MATLAB and conducted voice pick-up tests in an anechoic chamber before finalizing the placement of the mics.
Step 3: Speaker & Audio Output Engineering
Just as important as input is audio output. The speaker system had to provide rich music audio and crystal-clear voice playback in a compact package.
Our Method of Design:
- Chamber of Acoustics Modeling: Frequency response was simulated using CAD tools.
- Speaker Drivers: Two 1.5″ neodymium magnet full-range drivers
- Class-D stereo amplifier with DSP tuning for bass amplification
- Thermal Management: To avoid overheating, heat sinks are integrated into the PCB design.
The outcome? At maximum volume, balanced music playback with distortion under 1% THD and clear voice prompts are provided.
Step 4: Signal Processing and Firmware Integration
After the hardware was completed, we created firmware and embedded software for controlling the audio signal chain:
- Front End Audio (AFE): Noise reduction, adaptive gain control (AGC), and voice activity detection (VAD)
- Modules of Firmware: DSP setup, AVS SDK integration, and the audio driver stack
- Power Management: Adjusting power levels dynamically in response to audio activity
For firmware improvements after launch, we also added support for OTA (Over-The-Air) updates.
Step 5: Smart Features & IoT Integration
The gadget was upgraded with clever IoT features to go beyond audio:
- Sensor Fusion: Combining light, humidity, and temperature sensors
- Automation Triggers: Personalized actions triggered by sensor and voice inputs
- Companion App: Designed for iOS and Android to manage audio settings and smart actions
- Security features include a microphone mute switch with LED feedback and TLS-based secure communication.
To enable cloud-based firmware diagnostics, voice logging, and device authentication, our team collaborated with cloud service providers.
Step 6: Testing and Validation
Without thorough testing, no audio product design service is finished:
- Testing for Audio Quality: Real-world reverberation mapping and anechoic chamber tests
- Support for Certification: RoHS, FCC, and CE compliance for markets in the US and the EU
- Field Testing: Evaluate deployments for user interaction and environmental data in 50 homes.
- AI Training: We were able to remove last-mile bugs and guarantee mass production readiness by improving the wake-word engine using real-world data and machine learning retraining.
Build the Next-Gen Voice IoT
Business Outcomes
The last smart IoT audio product surpassed client expectations on every metric:
More than 100,000 units were sold in the six months following launch. Positive evaluations emphasized the device’s elegant form factor, intelligent responsiveness, and audio clarity. The client greatly expanded their clientele and landed new retail partnerships.
Why Choose Silicon Signals for Audio Product Design?
Our specialty at Silicon Signals is Audio Product Design Service, which help you turn your idea into a mass-market product.
- Expertise in Deep Audio: From DSP tuning to microphones
- Embedded Systems Integration: combining connectivity, IoT, and audio in one location
- End-to-End Support: From prototyping to production: comprehensive assistance with scalability and compliance
- Platform Experience: Experience with Qualcomm, MediaTek, NXP, TI, Nordic and many other platforms
We have the equipment, personnel, and procedure to deliver whether you’re creating an industrial voice assistant, wearable audio device, smart speaker, or medical audio system.