Puberphonia is the inappropriate persistence of higher-pitched prepubertal voice long after puberty and normal voice change. Also called mutational falsetto. Such individuals maintain something like their high-pitched, childhood voice by speaking in falsetto register.
The cause of puberphonia is never known with precision. Some think the condition arises more often in men whose voices mutate to the normal and mature male quality suddenly and precipitously, dropping abruptly into the bass or bass-baritone range. It is as though the person isn’t given time to adapt to the new sound of the voice. Some individuals with puberphonia can produce normal voice on request, but consider it “ugly,” or even their “monster voice.” Others need considerable coaching to find the normal voice. Once convinced by voice experts that the “monster” voice actually sounds great and is the “normal” one, most individuals can adopt the new voice fairly rapidly. The process of normalization typically involves only two or three sessions of speech/voice therapy, provided the therapist is highly voice therapy-qualified and experienced.
Falsetto register (1 of 6)
A 20-something man with puberphonia. Here, in distant view, he is in falsetto register at F#3 (185 Hz). His low falsetto is, by the way, remarkably stable and capable. Compare the vibratory blur with the next photo.
Chest register (2 of 6)
At virtually the same pitch, but now in chest register. Firmer closure (and longer closed phase of vibration explains the more-adducted blur as compared with photo 1.
Falsetto, open phase (3 of 6)
Now back to falsetto register under strobe light, and with better magnification. This is open phase of vibration also at F#3. Note the single, thinned "leading edge" of each fold.
Falsetto, "closed" phase (4 of 6)
Closed phase at the same pitch isn't in fact fully closed, and the "closed" phase of vibration is also shorter than in photo 6.
Chest, open phase (5 of 6)
Open phase of vibration at the same pitch, but in chest register. Note the fatter, grey vocal cord margin. Compare with photo 3.
Chest, closed phase (6 of 6)
Closed phase still in chest register is fully closed and it takes longer for the vocal cords to part for the next vibration; that is, the closed phase of vibration is longer. Tighter closure and longer closed phase explain why the blur between the cords seen in photo 2 is different than in photo 1.