Decibel Dosimeter/Headphone Cutout

The length of time it takes to sustain hearing damage drops off rapidly the louder the sound is. The loudest sounds can cause damage in an instant.

However, even a seemingly painless, tolerable level can be damaging after say 8 hours of exposure. Your local OHS authority no doubt has the tables.

What I propose here is a system of two devices.

1. The Decibel Dosimeter.

A tiny dB meter and data logger on a chip, which can be worn either behind the ear or as a natty ear-ring. It logs dB level against time exposed.

2. Exposure limiting headphones.

These would be integrated ambient noise cancellation 'phones and stereo 'phones you can plug into your walkperson/iDevice. An embedded CPU in the earmuff reads the dB exposure log from the 'meter.

As the exposure approaches damaging amounts, the 'phones crank down a limiter which keeps your personal stereo at a safe level, accounting for what you've already been exposed to.

So if you've already been exposed to 8 hours in a foundry, you won't be able to destroy your hearing (further) by cranking Def Leppard (Def Jam/Def Penalty Kru) on the bus home.

Having the logger separate from the 'phones allows it to log exposure from any source, including that played through the 'phones.