Human BeatBoxing : A Vocal Exploration

Alexis Dehais-Underdown – alexis-dehais-underdown@sorbonne-nouvelle.fr
Paul Vignes – vignes.paul@gmail.com
Lise Crevier-Buchman – lise.buchman1@gmail.com
Didier Demolin – didier.demolin@sorbonne-nouvelle.fr
Université Sorbonne-Nouvelle
13, rue de Santeuil
75005, Paris, FRANCE

Popular version of paper ‘3aSC7’
Presented Wednesday morning, December 1st, 2021
181th ASA Meeting, Acoustics in Focus

We are interested in exploring the potential of the human vocal tract by understanding beatboxing production. Human Beatboxing (HBB) is a musical technique that uses the vocal tract to imitate musical instruments. Similar to languages like French or English, HBB relies on the combination of smaller units into larger ones. Unlike linguistic systems, HBB has no meaning: while we speak to be understood, beatboxers do not perform to be understood. Speech production obeys to linguistic constraints to ensure efficient communication, for example, the fact that each language have a finite number of vowels and consonants. This is not the case for HBB production because beatboxers use a larger number of sounds. We hypothesize that beatboxers acquire a more accurate and extended knowledge on physical capacities of the vocal tract that allows them to use a larger number of sounds.

Acquisition of laryngoscopic data (left) and acoustic & aerodynamic data (right)

We use 3 technics on 5 professional beatboxers : (1) aerodynamic recordings, (2) laryngoscopic recordings and (3) acoustic recordings. Aerodynamic data gives information about pressure and airflow changes that are the result of articulatory movements. Laryngoscopic images give a view of the different anatomical laryngeal structures and their role in beatboxing production. Acoustic data allows us to investigate the sound characteristics in terms of frequency and amplitude. We extracted 9 basic beatboxing sounds from our database: the classic kick drum and its humming variant, the closed hi-hat and its humming variant, the inward k-snare and its humming variant, the cough snare and the lips roll and its humming variant. Humming is a beatboxing strategy that allows simultaneous and independent articulation in the mouth and melodic voice production in the larynx. Some sounds are illustrated here :

The preliminary results are very interesting. While speech is mainly produced on an egressive airflow from the lungs (i.e. exhalation phase of breathing), HBB is not. We found a wide range of mechanisms to produce basic sounds. Mechanisms were described by where the airflow was set in motion (i.e. lungs, larynx, mouth) and by which direction the airflow goes (i.e. in or out of the vocal tract). Sounds shows different combinations of airflow location and direction :
• buccal egressive (humming classic kick and closed hi-hat) and ingressive (humming k-snare and lips roll)
• pulmonic egressive (cough snare) and ingressive sounds (classic inward k-snare and lips roll),
• laryngeal egressive (classic kick drum and closed hi-hat) and ingressive (classic k-snare and inward classic kick drum).

A same sound may be produced differently by different beatboxers but may sound perceptually similar. HBB displays high pressure values that suggests these mechanisms are more powerful than speech ones in a quiet conversation.

In the absence of linguistic constraints, artists are exploiting the vocal tract capacities more freely. It raises several questions about how they reorganize the respiratory activity, how they coordinate sounds together and how beatboxers avoid lesions or damages of the vocal tract structures. Our research project will produce further analysis on the description and coordination of beatboxing sounds at different speed rates based on MRI, Laryngoscopic, Aerodynamic and Acoustic data.

 

 

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