My issue is getting around not being able to use a microcontroller. I tried connecting a the sensors out put to a speaker and I got some static initially and then nothing. Do I need to build a circuit which produces noises, such as a beep, and have it hooked up between the sensor and the speaker, or am I dead in the water without a microcontroller. Also, its not important that the user know the distance between them and the object, just that when the noise gets louder as their getting closer or softer and farther away.
Thanks