• In singing and in speech you have always a mix of regular and irregular waves. This mix gives you the 'tessitura' or individual texture and is almost independent of pitch and vowel, so you can remember a voice by this texture. For a far reach of the waves sent from the person it is important to emit high frequencies, the 'brilliance 'or 'ringing,' because our ears are conditioned to te hear these frequencies (about 3 kHz = the singing formant) with priority. The more you are aware of your singing formant the less you will be urged to use pressure for your voicing.

Thank you, Uta for your interesting answer. Hazim.

I think there are a lot of potential answers to your question, based on the context of why you asked it in the first place. Audio forensics use software to compare voices to a database of millions of voices to measure the likelihood of a recorded voice being a specific person. See https://www.livescience.com/19506-audio-forensics-reveals-voices-secrets.html

In the realm of performance, actors rely on a range of vocal quality features in order to “transform” to sound different from the way they usually do. For example, they might add qualities such as “nasality” or “denasality” or “orality” to change the nature of their voice. They may implement greater “twang”, which is related to the higher frequencies (aka “the singer’s formant” which was first described by Sundberg) Uta was describing. Though they may adopt linguistic features, by changing their accent or modifying their lexicon, voice quality is at a deeper level. Other qualities include breathiness, harshness, brightness/dullness, etc. These are primarily subjective terms for the resonance qualities that Uta was discussing, that are shaped by the speaker’s vocal mechanism (anatomy) and how the speaker uses it.