Are the Roland CS-10-EM binaural microphones headphones?

They can be used as headphones, but their intended use is as microphones. You simply wear them like headphones and connect them to a portable recorder like a Roland R-07 to capture a stereo recording from a first person perspective and can get instant playback of your audio through the headphones/microphones. This a technique popular in field recording for film and TV sound and sample libraries.

What's the frequency response of the M-100 AIRA Headphones?

The M-100s have an extremely wide frequency response of 5–30,000 Hz that offers a clear sound that doesn't distort on very low sub basses and extreme higher frequencies.

What's the most affordable set of Roland headphones?

The most affordable are the RH5 headphones, ideal for monitoring electronic and acoustic instruments as well as for general listening. They are probably the best quality affordable headphones available.