Raj Patel, Product Director at an industrial safety equipment company, meets Sarah Chen, Head of Product at a wearable technology firm, at a hardware engineering conference to discuss audio solutions for industrial environments.
The Conference Meeting
Raj Patel: Sarah, I keep running into the same problem. Our field teams need comms audio, but they also need to hear what's happening around them. Earbuds are a safety hazard on an active site.
Sarah Chen: We dealt with the exact same tension. Audio quality versus situational awareness — pick one. That was the tradeoff until we found a team that could actually engineer bone conduction properly.
Raj Patel: You went the bone conduction route? The commercial products I've tested are... underwhelming. Thin audio, uncomfortable after an hour, too fragile for real work environments.
Sarah Chen: That's why we didn't use a commercial product. We had Big0 engineer one from scratch.
The Technical Requirements
Raj Patel: From scratch — meaning custom electronics, custom enclosure, everything?
Sarah Chen: Everything. The transducer, the amplifier circuit, the PCB, the enclosure, the firmware. When you need specific performance in a specific form factor, off-the-shelf modules don't cut it.
Raj Patel: What drove that decision? Custom hardware is expensive.
Sarah Chen: We tried adapting existing products first. Consumer bone conduction headsets are designed for jogging — they're optimized for music, not voice intelligibility. And they fall apart in industrial conditions. We spent months trying to make modifications work before accepting that the foundation was wrong.
Raj Patel: So you needed voice-optimized audio in a form factor that fits under a hard hat?
Sarah Chen: Under a hard hat, under a tactical helmet, inside hearing protection. The form factor constraints were strict. And the audio had to be clear in environments above 85 decibels.
The Development Process
Raj Patel: Walk me through how they approached it.
Sarah Chen: They started with the transducer — which bone conduction driver, at what frequency response, driven by what amplifier profile. That's the core physics. Get that wrong and nothing else matters.
Raj Patel: How do you optimize for speech versus music?
Sarah Chen: Different frequency emphasis. Speech intelligibility peaks in a narrower band than music reproduction. Big0 tuned the amplifier and firmware DSP to prioritize voice frequencies. The result sounds worse for music and better for understanding someone talking to you — which is exactly the right tradeoff.
Raj Patel: What about the PCB?
Sarah Chen: Custom board integrating the amplifier, Bluetooth module, battery management, and microphone. They got it small enough to sit behind the ear without feeling like you're wearing a brick. Multiple revision cycles to get the layout right — component placement affects both electrical performance and thermal management in something that small.
The Prototyping Approach
Raj Patel: How many prototype iterations?
Sarah Chen: Several for the enclosure. 3D printing let them test a new form factor every few days. The critical variable was contact pressure — how firmly the transducer presses against the temporal bone. Too light and you lose audio. Too heavy and it's uncomfortable within thirty minutes.
Raj Patel: That's a narrow window.
Sarah Chen: Very narrow. And it has to work across different head sizes and shapes. The mounting mechanism went through its own iteration cycle independent of the enclosure shape.
Raj Patel: What about environmental testing?
Sarah Chen: Noise testing at different dB levels, Bluetooth range testing, battery life characterization, drop testing. They built a structured test protocol and ran every prototype revision through it. No guessing about whether a change actually improved things.
The Deliverable
Raj Patel: What did they hand over at the end?
Sarah Chen: Complete engineering package. Schematics, PCB layouts, bill of materials with specific part numbers and suppliers, 3D models ready for injection molding tooling, firmware source code, test reports. Everything a contract manufacturer needs to produce units.
Raj Patel: So you could take that package to any CM and get production units made?
Sarah Chen: That was the point. Big0 handled the engineering. We choose the manufacturing partner. No vendor lock-in, no proprietary dependencies. We own every file.
Raj Patel: How long from kick-off to that deliverable?
Sarah Chen: Faster than our previous hardware projects, and those used more conventional technology. The 3D printing approach for enclosure iteration saved significant time compared to traditional tooling cycles.
The Recommendation
Raj Patel: Sarah, I've been evaluating three approaches — adapt a commercial product, license a reference design, or custom engineer. You're telling me custom was the right call?
Sarah Chen: For our requirements, absolutely. If you need standard consumer specs, buy off the shelf. If you need specific performance in a specific form factor for a specific environment — custom engineering pays for itself because you don't spend months trying to make the wrong product work.
Raj Patel: And Big0 handles the full stack — electronics, mechanical, firmware?
Sarah Chen: One team, one integration. No finger-pointing between an electronics vendor and a mechanical vendor and a firmware contractor when something doesn't work. They own the whole problem.
Raj Patel: That's what I need. Our field teams deserve better than consumer products duct-taped into industrial service.
Sarah Chen: Get your requirements documented — form factor constraints, audio specs, environmental conditions, target cost. The clearer your brief, the faster they can move.