need help to build a voltage controlled volume control

there are a couple of voltage controlled amplifiers ( VCA ) Lying around see Texas, National, Analog Devices.

another solution is the use of a jfet driven by the noise level in the feedback network of an op-amp

Or indeed very simply a resistor output photocell designed for audio in fact.

Graham

Few thoughts:

1. Many "highway" motorcycle travelers use earplugs to protect their ears from windnoise. It *will* make you deaf in the long run. You actually want to "overpower" the windnoise with music? No headphone earplugs I know off will actually dampen the ambient noise much. If you know some that damp wind by ~ 15 dB (like my Alpine earplugs) *and* play music - I'm all ears :-)

Any noisecancelling solutions in existence (helmet compatible)?

1. 5 Watts in an earplug? Your eardrums will blow out of your nose smoking! 100mW will do permanent damage over a short time.

1. I actually tried it with fixed volume and in-ear headphone. It was set unbearably loud at traffic lights; but I could not hear the music on the highway any more. That made me think..

2. I removed the windshield from my cycle. Slightly more windpressure on my body, and a *lot* less noise in the helmet.

Have a safe ride!

Why not simply replace your earphones with noise-cancelling ones? You know, the ones sold for use on airplanes and such?

For examples:

Playing music loud enough to hear it over the ambient noise will ruin your hearing for sure.

In fact, the ambient noise isn't particularly good for your hearing. Some of the really big bikes with very high windscreens may be reasonably quiet.

René's post (elsewhere in the thread) is right on.

--Mac