What is vocal fremitus?

[scilearner]

Wiki: vocal fremitus, is a vibration felt on the patient's chest during low frequency vocalization.

 

Now my question is when you say something, is the vibration passed from larynx to trachea, then from bronchial tree to chest wall or is vocal fremitus referring to just the physical vibration that occurs in the chest when you say something. Thanks

[ewmon]

Fremitus is the low-frequency portion of the vocal spectrum that radiates from the chest. The sonic power produced by the vocal cords during voiced vocalizations propagates both upward through the vocal tract (throat, mouth, nose) which provides us with articulated (ie, formed) speech, and downward into the lungs/thorax. The word "voiced" means those vocalizations in which the vocal cords vibrate — this includes the vowels and the voiced consonants (eg, B, D and G where the vocal cords vibrate as compared to their unvoiced counterparts P, T and K where they don't vibrate). All sonic energy travels through the air in both directions, however, the mass of the lungs, rib cage, musculature and skin of the chest act as a low-pass filter, allowing only the low frequencies of the vocalization to pass through the chest wall.

[scilearner]

Fremitus is the low-frequency portion of the vocal spectrum that radiates from the chest. The sonic power produced by the vocal cords during voiced vocalizations propagates both upward through the vocal tract (throat, mouth, nose) which provides us with articulated (ie, formed) speech, and downward into the lungs/thorax. The word "voiced" means those vocalizations in which the vocal cords vibrate — this includes the vowels and the voiced consonants (eg, B, D and G where the vocal cords vibrate as compared to their unvoiced counterparts P, T and K where they don't vibrate). All sonic energy travels through the air in both directions, however, the mass of the lungs, rib cage, musculature and skin of the chest act as a low-pass filter, allowing only the low frequencies of the vocalization to pass through the chest wall.

 

Thanks that was a great explantion . So does this mean when we use low frequency sounds, sound is produced both in mouth and chest area, wouldn't these affect the quality of the sound produced because it comes from 2 areas.

[ewmon]

We don't actually "use" sounds, but we produce them at the vocal cords and at a few points along the vocal tract.

 

Most of the sounds originate at the vocal chords. The shape of the vocal tract boosts and suppresses certain frequencies, and tight restrictions at points along the tract (back of the mouth, teeth on lips, etc) adds certain frequencies, thus providing the majority of our speech — which is why we place microphones in front of the mouth.

 

We always produce low frequency sounds, and they come out of the mouth and also through the chest wall. I don't understand the idea of fremitus affecting the "quality" of the sound. Fremitus is natural, and we're supposed to hear it. Having two sources of sound would not necessarily degrade its "quality" — it's certainly not true with stereos or quadraphonic systems. When we hear recordings from microphones, mostly likely, we are not hearing as much of the fremitus as we would from being present when the person was talking or singing. This *might* be why we can usually tell if a voice from the other room is the radio/TV/sound system or a live person.

 

In a crude, non-exact sense, the drone pipes of bagpipes are *somewhat* analogous to fremitus, while the chanter of bagpipes (the fingered melody pipe) is *somewhat* analogous to the vocal tract. The speaker can adjust the vocal tract, but the fremitus is pretty much fixed.