The perceived traits of a voice, such as being dark, light, or heavy, are primarily influenced by several acoustic properties of sound waves and the mechanical aspects of speaking or singing. Here are some factors that can contribute to these traits:
Fundamental frequency (Pitch): The fundamental frequency refers to the rate at which the vocal folds vibrate, determining the pitch of the voice. A lower fundamental frequency tends to create a darker or heavier voice, while a higher fundamental frequency contributes to a lighter or brighter voice.
Harmonics: Harmonics are multiples of the fundamental frequency that create the overall timbre or tone color of the voice. The presence and distribution of harmonics can affect the perceived darkness or lightness of a voice.
Resonance: Resonance refers to the amplification and modification of sound waves in the vocal tract. The shape and size of the vocal tract, including the pharynx, oral cavity, and nasal cavity, play a crucial role in shaping the resonant frequencies. Different resonant frequencies can influence the perceived quality of the voice.
Vocal fold characteristics: The thickness, length, and tension of the vocal folds can contribute to the voice's traits. Thicker and longer vocal folds generally produce a darker or heavier voice, while thinner and shorter folds can result in a lighter or brighter voice.
Articulation: The precise movements and positioning of the articulators (tongue, lips, jaw, etc.) during speech or singing affect the resonance and articulatory features of the voice. These aspects can influence the perceived timbre and weight of the voice.
It's important to note that individual vocal characteristics and techniques, such as breath support, vocal placement, and vocal technique, also play significant roles in shaping the traits of a voice. Vocal training and practice can help singers and speakers develop control over these aspects to achieve their desired vocal qualities.