The timbre of the voice as perceived by the singer him-/herself.

Fifteen professional singers sang simple vocal exercises at different pitches. The sung excerpts were recorded, and seven modified versions were created from each recording. The modifications were then played to the participant and (s)he had to assess the similarity of these stimuli to the perception of his/her own voice during the act of singing. Participants rated as most similar those stimuli which were modified by the filter whose frequency response most closely resembled a trapezoid, which was created by taking into account 1) the diffracting air conduction component from the mouth of the singer to his ear channel, 2) the bone conduction component, and also 3) the influence of the stapedius reflex on the sensitivity of his/her auditory system.