US 6,420,975 · Granted 2002-07-16
The Mirror Mic That Makes Your Car Calls Crystal Clear
Imagine a microphone built into your car's rearview mirror that's smart enough to filter out engine noise and road rumble, leaving only your voice for phone calls. It's like having a personal sound editor sitting between you and the windshield, boosting your words while muting the chaos.
The plain-English version
What it protects
The claim covers a digital sound processor mounted in or near a vehicle's interior rearview mirror that filters and enhances voice signals while suppressing background noise from the vehicle environment. What's protected here is the specific combination of microphone placement within an accessory module attached to the windshield, the signal processing algorithm that boosts vocal-to-noise ratio, and an optional indicator that shows the driver the quality of their incoming signal in real time.
Why it matters
This patent addresses a real problem that frustrated early cell phone users in cars: every call sounded like you were shouting from inside a jet engine. By anchoring the microphone to the mirror and building intelligence into the processing, Donnelly created a solution that could be installed at the factory or added later. This kind of foundational work on in-car audio quality became table stakes as hands-free calling became legally and practically essential.
Real-world use
Every time you take a hands-free call while driving and the person on the other end hears your voice clearly instead of road noise, that's the kind of filtering this patent was engineered to handle.
Original USPTO abstract
A digital sound processor is provided to enhance the vocal to non-vocal noise ratio of the signal processed by a vehicle audio system such as a cellular telephone, emergency communication device, or other audio device. Optionally, an indicator is provided for use with the vehicular audio system in order to provide a user of the audio system with a status signal relating to a reception quality of a vocal signal from the user. The microphone of the audio system may be mounted within an accessory module, which may be mounted to an interior surface of a vehicle windshield. The accessory module provides a fixed orientation of the microphone and is easily installed to the vehicle as it is manufactured or as an aftermarket device. The indicator may be mounted at the accessory module or elsewhere at the mirror assembly.
Patent details
- Publication number
- US 6,420,975
- Filing date
- 1999-12-17
- Grant date
- 2002-07-16
- Assignee
- Donnelly Corporation
- Inventor(s)
- DELINE JONATHAN E., LYNAM NIALL R., SPOONER RALPH A., MARCH PHILLIP A.
- CPC class
- B60R1/12
Want to file your own patent?
If you're designing a new automotive gadget with built-in microphones or audio processing, search our free patent database to see what's already claimed in this crowded space.
Free patentability scan