As it applies to singing and the human voice, a subharmonic is one or several harmonics created below the fundamental harmonic where the fundamental is perceived to be lower than the original tone. Subharmonics occur when a singer’s ventricular folds vibrate along with their vocal folds at the same time.
It’s important to note here that the label “subharmonic” does not refer to a register or specific vocal technique. Just because you have a voice in a low register doesn’t mean you are necessarily using subharmonics. Rather, it is the result of the vocal technique you use.
First… What is a Subharmonic?
The subharmonic is generated when two notes with the specific frequencies interact or periodically connect with one another. This means that subharmonics can be generated when the two notes are coming from the same source and place or as close as possible so that the listener perceives it as only one wave of sound.
There are three distinct techniques that create subharmonics: vocal fry, kargyraa, and growl. Let us dig a little deeper into vocal fry, dividing vocal fry into three states: compressed, supported, and open.
Compressed Vocal Fry
A compressed vocal fry is used by many people in terms of speech, typically at the trail end of spoken phrases. Some use it judiciously while others use it without even realizing it. Regardless of the user, there is no support or breath pressure because the folds are fully adducting but are also thick, short, and slack – proper phonation is no longer possible at this point because the voice is squeezed so tight and is pressed down.
The only way for someone to create sound in this predicament is to allow puffs of air to push through the folds which in turn causes them to bubble through, thus the term vocal fry. The sound is thin, weak and unsupported, and no actual pitch can be identified.
Supported Vocal Fry
A supported vocal fry sounds thin in comparison to full voice and tends to have a lot of rattle and some instability in pitch; nonetheless, it usually does not suffer from vocal break like falsetto or open vocal fry. The sound feels as if it is centered around the mouth area with a lot of resonance in the suprasternal notch area between the throat and collar-bone.
Open Vocal Fry
An open vocal fry is where the user is able to sustain both full voice and a supported vocal fry at the same time. Technically, one fold vibrates at one frequency and the other vibrates a perfect fifth above, creating the subharmonic. In order to produce the desired note, one must sing up the octave when using an open vocal fry. It is the subharmonic singing sound that you may have heard of before online if you do a quick YouTube search.
It sounds very similar to full voice, but with a different color. Some people have referred to this sound as strohbass and others would call it a loud fry; technically speaking, both are correct since strohbass refers to the crackling sound that straws make and loud fry refers to the volume and the quality of full voice.
Subharmonics are Harmonics Heard Below the Fundamental Tone
Subharmonics are harmonics below the fundamental and can be created with instruments, electronics, the voice, or any sound producing agent. It does have to come from the same source, space, and time with the correct waves periodically interacting with each other in order for someone to hear it. Subharmonic singing is a fascinating area, and is something worth looking closer at, even if you don’t use subharmonic singing in your everyday vocal practice.