Midvoice IIA (Mutation Climax Stage): There is a clear decrease (absence) in the number of upper partials in this boy’s voice and even his lowest partials are quite weak (fundamental frequency). He is in the peak stage of mutation in his vocal folds and so he is experiencing a peak of vocal instability. Very little vibrato is produced, perhaps reflecting a generally weakened state in the internal muscles of the larynx.Read More →