Noel N Hanna

Experimental determinations of the acoustic properties of the subglottal airway, from the trachea below the larynx to the lungs, may provide useful information for detecting airway pathologies and aid in the understanding of vocal fold auto-oscillation. Here, minimally invasive, high precision impedance measurements are made through the lips (7 men...

During speech and singing, the vibrating vocal folds are acoustically loaded by resonant ducts upstream (the trachea) and downstream (the vocal tract). Some models suggest that the vocal fold vibration (at frequency fo) is more stable at frequencies below that of a vocal tract resonance, so that the downstream load is inertive (mass-like). If so, v...

The frequencies, magnitudes, and bandwidths of vocal tract resonances are all important in understanding and synthesizing speech. High precision acoustic impedance spectra of the vocal tracts of 10 subjects were measured from 10 Hz to 4.2 kHz by injecting a broadband acoustic signal through the lips. Between 300 Hz and 4 kHz the acoustic resonance...

Players control a range of parameters in the player-instrument system. First we show how loudness and pitch vary over the plane of mouth pressure and force on the reed of a clarinet, and thus how these parameters can be used in compensation to produce trajectories in this plane that have varying loudness and timbre but constant pitch. Next we prese...

Speech and singing are of enormous importance to human culture, yet the physics that underlies the production and control of the voice is incompletely understood, and its parameters not well known, mainly due to the difficulty of accessing them in vivo. In the simplified but well-accepted source-filter model, non-linear vocal fold oscillation produ...

The trombone and the male voice cover similar frequency ranges and, at a physical level, the basic anatomies of the voice and the trombone show some qualitative similarity: both have two vibrating flaps of muscular tissue (the vocal folds and the trombonist’s lips, respectively), and in each case, these are loaded acoustically by resonant ducts bo...

Purpose Over a range roughly C5–C6, sopranos usually tune their first vocal tract resonance (R1) to the fundamental frequency (f o) of the note sung: R1:f o tuning. Those who sing well above C6 usually adjust their second vocal tract resonance (R2) and use R2:f o tuning. This study investigated these questions: Can singers quickly learn R2:f o tun...

No PDF available ABSTRACT The acoustic impedance spectrum of the vocal tract and trachea is important in speech and singing. The operation of musical wind instruments depends on the impedance spectra of their bores, and sometimes also on the impedance spectra of the player’s vocal tract. Here, we describe two measurement techniques. The three micro...

The first resonance of the vocal tract (R1, an impedance minimum when measured at the lips) is tuned by some singers: all of the sopranos we have studied, whether trained or not, tune R1 to fo over the range roughly C5 to C6; altos and tenors sometimes tune it to one of the lower harmonics in their upper range. Sopranos who sing in the range substa...

Broadband excitation of the vocal tract at the lips (Epps, Smith & Wolfe, 1997. Meas. Sci. Technol. 8, 1112–1121 [1]) has been used by the present authors and in other laboratories to estimate the resonances of the vocal tract in ‘ecological’ conditions of speaking and singing. A sound source and microphone are both held at the lower lip of the sub...

Determining the area function A(x) of the airway between the lips and vocal folds from external measurements is a classic inverse problem. A(x) is estimated by fitting the acoustic impedance measured through the lips. Excellent fits are possible with about eight cylindrical segments representing the tract. In examples where A(x) has only small slop...

We describe a method to deduce pressure and flow at the glottis from acoustic measurements near or downstream from the lips, using phonation into a cylindrical duct with three microphones. In this paper this method is tested on hard one-dimensional ducts, also reporting the precision of using 3D printed models of vocal tract area functions. Combini...

youtu.be/wZpjmqkgEYk Discover how physics and anatomy combine to produce the human voice. Date: Friday, 7 April 2017 The unique sound of the voice starts with a breath of air. Transforming the energy in this air allows us to communicate, entertain and express our identity, mood and personality. Yet, we don’t really know how it works. To celebrate W...

Acoustic impedance spectrometry using the three-microphone, three-calibration technique has recently been applied to the vocal tract during phonation (Hanna et al., 2016. JASA, 139, 2924–2936). The qualitative and quantitative similarity of the impedance spectrum of the vocal tract with a simple cylindrical duct prompts the question: How well do ge...

Oscillating vocal folds are acoustically loaded by resonant ducts upstream (trachea) and downstream (vocal tract). The soprano frequency range covers the first resonance in each duct; indeed, sopranos often tune their vocal tract resonance (R1) near the singing frequency. What happens when R1 is removed? In this study, sopranos sang into an acousti...

The acoustic impedance of the vocal tract filter was measured in vivo from 10 to 4200 Hz with the glottis closed and during phonation. Frequencies, magnitudes and bandwidths were measured for the acoustic and for the mechanical resonances of the surrounding tissues. The energy losses in the vocal tract were five-fold higher than the visco-thermal l...

Objet. Dans la voix normale, la vibration des plis vocaux est complexe car multifactorielle. Un modèle expérimental, anatomique et mécanique, permettrait une meilleure compréhension de ces mécanismes. Cette étude préliminaire se propose de valider un banc d’essai construit autour de larynx excisés. Méthodes. Onze larynx humains prélevés à 48 heure...

The fundamental frequency of the singing voice is controlled by biomechanical and aerodynamical laryngeal parameters. In this ex vivo study, we have independently simulated several of these control parameters, namely subglottal pressure, vocal fold extension and arytenoid compression, using excised human larynges in order to investigate the fluid-s...

Invited presentation

The aeroacoustic properties of the vocal folds and tract are difficult to measure directly. Here, they were measured using broad- and narrow-band excitation at the mouth during phonation into various acoustic loads, including a non-resonant load provided by an acoustically infinite waveguide with cross section comparable with that of the tract. The...

The bandwidths of vocal tract resonances are critical: too narrow allows speech harmonics to miss resonances, too broad gives insufficient boost to identify phonemes.

The impedance spectrum of the vocal tract was measured at the lips from 10 Hz to 4.2 kHz using the three-microphone, three-calibration technique. A broadband signal synthesised from sine waves allows high precision measurements irrespective of the fundamental frequency of phonation. From these measurements, the frequencies, magnitudes and bandwidth...

Conference presentation at ICVPB