Hi I'm new to sound generation.

I'm trying to make a pitch pipe sound that is reliable for a singer with an Android phone.

So far, I have an oscillator that outputs whatever frequency I want to input.

When the frequency is low like the pitch C3, I do not hear anything.

Also, the volume is not consistent for different pitches.

Thank you in advance for trying to help me.

If your oscillator is just an [osc~] you won't get any interesting result. There are different synthesis techniques, you'll find a good overview there :

http://www.pd-tutorial.com/english/index.html

Try using square or triangle waves and filter them to get the sound you want, you'll get a more consistent sound if you change the cutoff filter with the pitch.

This is just general information, I don't really know how a pitch pipe is supposed to sound. Don't hesitate to attach your current patch.

Here's the pitch pipe sound I want to emulate:
http://www.harmonize.com/metropolis/images/Sounds/CNatural.mp3

The patch I made is a derivative of the GuitarTuner Android app example.

I'm new to the waves and filtering. Hopefully the pitch pipe example helps you
to explain what waves and filters would get that sound.

http://www.pdpatchrepo.info/hurleur/pitchpipe.pd