500hz to 3000hz tone tester

[freddy_uk]

hi,

i have just gone out and got a cable tester from maplins, works like an inductive amplifier, detecting a tone present in the cable. Im detecting tones from 500hz to 3000hz.

I want to take to audio speaker output of this tester and put it through some kind of filter, when a tone between 500hz and 3000hz is detected i want to light an led, the unit is powered by a pp3 battery.

ideally im looking to filter out all the ac hiss and hum and just have an led light when tones between 500hz and 3000hz are detected

Any suggestions

thanks
freddy