Not to come to umd defense but it is illegal to ride in Illionis with a headset in (other then a cellphone headset or hearing aid).

Illinois law states that you may not wear a headset while driving. Headsets are defined as any device, other than a hearing aid, that allows the wearer to hear or receive electronic communications. (The use
of a single-sided headset or earpiece with a cellular or other mobile telephone is permitted.) Motorcycle, motor-driven cycle and moped operators may use intercom helmets that permit drivers and/or passengers to speak to one another.

And since you are required to follow the rules of the road this would apply to cyclist too.

(Also interesting umd is putting for a legal argument while starting a thread about no handed riding which is illegal in most states.)