Does anyone know of a small passive audio potentiometer?

I have been looking for a small audio potentiometer, which would fit seamlessly with my headphones. I have some example pictures of something that I was thinking of. I want a simple cable which has an input headphone jack on one end (male), and the female connector on the other end so I can plug in my headphones. I have examples, but they are just too large and obtrusive.

I know that there are small slide potentiometers and was wondering if it would possible to make something like this, or if there is something commercially available. If someone with circuitry knowledge would be able to advise me on how to approach this it would be much appreciated.

I like the way some headphones have volume controls which have buttons, but those control the device's volume, and that size would be what I was looking for, but with a slide potentiometer.

Any help is very appreciated,

Picture of Does anyone know of a small passive audio potentiometer?
All potentiometers are "passive", what you need to find is one with an "audio" or "log" taper, and, for stereo, it must be a twin track pot too. Bear in mind this can only make the phones quieter.