A Speaker Hears him/her self through two Channels: Air and Bone.
Channel 1 is the air through which sound waves travel. Everyone hears those sounds including the speaker.
Channel 2 (for the speaker only) are the bones of the skull through which his/her own speech sounds travel.
That is why when we speak, we hear ourselves slightly differently than the rest of humanity.
When we hear ourselves for the first time through only one channel (as through a playback from a tape recorder) it is typically amusing since we are not used to hearing ourselves sound that way.