scholarly journals Dolphin whistles: a functional misnomer revealed by heliox breathing

2011 ◽  
Vol 8 (2) ◽  
pp. 211-213 ◽  
Author(s):  
P. T. Madsen ◽  
F. H. Jensen ◽  
D. Carder ◽  
S. Ridgway
Keyword(s):  
Fundamental Frequency ◽  
Bottlenose Dolphin ◽  
Sound Production ◽  
Large Range ◽  
Impedance Matching ◽  
Vocal Learning ◽  
Vocal Folds ◽  
Terrestrial Mammals ◽  
Nasal Tissue ◽  
Air Density

Delphinids produce tonal whistles shaped by vocal learning for acoustic communication. Unlike terrestrial mammals, delphinid sound production is driven by pressurized air within a complex nasal system. It is unclear how fundamental whistle contours can be maintained across a large range of hydrostatic pressures and air sac volumes. Two opposing hypotheses propose that tonal sounds arise either from tissue vibrations or through actual whistle production from vortices stabilized by resonating nasal air volumes. Here, we use a trained bottlenose dolphin whistling in air and in heliox to test these hypotheses. The fundamental frequency contours of stereotyped whistles were unaffected by the higher sound speed in heliox. Therefore, the term whistle is a functional misnomer as dolphins actually do not whistle, but form the fundamental frequency contour of their tonal calls by pneumatically induced tissue vibrations analogous to the operation of vocal folds in terrestrial mammals and the syrinx in birds. This form of tonal sound production by nasal tissue vibrations has probably evolved in delphinids to enable impedance matching to the water, and to maintain tonal signature contours across changes in hydrostatic pressures, air density and relative nasal air volumes during dives.

scholarly journals Vocal Creativity in Elephant Sound Production

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 750
Author(s):  
Angela S. Stoeger ◽  
Anton Baotic ◽  
Gunnar Heilmann
Keyword(s):  
Cognitive Abilities ◽  
Positive Reinforcement ◽  
Sound Production ◽  
Vocal Learning ◽  
Learning Processes ◽  
Fine Tuning ◽  
Social Feedback ◽  
Nasal Tissue ◽  
Production Techniques ◽  
Production Mechanisms

How do elephants achieve their enormous vocal flexibility when communicating, imitating or creating idiosyncratic sounds? The mechanisms that underpin this trait combine motoric abilities with vocal learning processes. We demonstrate the unusual production techniques used by five African savanna elephants to create idiosyncratic sounds, which they learn to produce on cue by positive reinforcement training. The elephants generate these sounds by applying nasal tissue vibration via an ingressive airflow at the trunk tip, or by contracting defined superficial muscles at the trunk base. While the production mechanisms of the individuals performing the same sound categories are similar, they do vary in fine-tuning, revealing that each individual has its own specific sound-producing strategy. This plasticity reflects the creative and cognitive abilities associated with ‘vocal’ learning processes. The fact that these sounds were reinforced and cue-stimulated suggests that social feedback and positive reinforcement can facilitate vocal creativity and vocal learning behavior in elephants. Revealing the mechanism and the capacity for vocal learning and sound creativity is fundamental to understanding the eloquence within the elephants’ communication system. This also helps to understand the evolution of human language and of open-ended vocal systems, which build upon similar cognitive processes.

Frequency Modulation During Song in a Suboscine Does Not Require Vocal Muscles

2008 ◽  
Vol 99 (5) ◽  
pp. 2383-2389 ◽  
Author(s):  
Ana Amador ◽  
Franz Goller ◽  
Gabriel B. Mindlin
Keyword(s):  
Fundamental Frequency ◽  
Sound Production ◽  
Frequency Control ◽  
Vocal Learning ◽  
Sound Frequency ◽  
Mass Model ◽  
Interesting Insight ◽  
Highly Correlated ◽  
Frequency Modulations ◽  
And Control

The physiology of sound production in suboscines is poorly investigated. Suboscines are thought to develop song innately unlike the closely related oscines. Comparing phonatory mechanisms might therefore provide interesting insight into the evolution of vocal learning. Here we investigate sound production and control of sound frequency in the Great Kiskadee ( Pitangus sulfuratus) by recording air sac pressure and vocalizations during spontaneously generated song. In all the songs and calls recorded, the modulations of the fundamental frequency are highly correlated to air sac pressure. To test whether this relationship reflects frequency control by changing respiratory activity or indicates synchronized vocal control, we denervated the syringeal muscles by bilateral resection of the tracheosyringeal nerve. After denervation, the strong correlation between fundamental frequency and air sac pressure patterns remained unchanged. A single linear regression relates sound frequency to air sac pressure in the intact and denervated birds. This surprising lack of control by syringeal muscles of frequency in Kiskadees, in strong contrast to songbirds, poses the question of how air sac pressure regulates sound frequency. To explore this question theoretically, we assume a nonlinear restitution force for the oscillating membrane folds in a two mass model of sound production. This nonlinear restitution force is essential to reproduce the frequency modulations of the observed vocalizations.

scholarly journals Adding colour-realistic video images to audio playbacks increases stimulus engagement but does not enhance vocal learning in zebra finches

2021 ◽  
Author(s):  
Judith M. Varkevisser ◽  
Ralph Simon ◽  
Ezequiel Mendoza ◽  
Martin How ◽  
Idse van Hijlkema ◽  
...  
Keyword(s):  
Visual Cues ◽  
Sound Production ◽  
Visual Stimuli ◽  
Vocal Learning ◽  
Song Learning ◽  
Frame Rate ◽  
Zebra Finches ◽  
Video Content ◽  
Biologically Relevant ◽  
Video Images

AbstractBird song and human speech are learned early in life and for both cases engagement with live social tutors generally leads to better learning outcomes than passive audio-only exposure. Real-world tutor–tutee relations are normally not uni- but multimodal and observations suggest that visual cues related to sound production might enhance vocal learning. We tested this hypothesis by pairing appropriate, colour-realistic, high frame-rate videos of a singing adult male zebra finch tutor with song playbacks and presenting these stimuli to juvenile zebra finches (Taeniopygia guttata). Juveniles exposed to song playbacks combined with video presentation of a singing bird approached the stimulus more often and spent more time close to it than juveniles exposed to audio playback only or audio playback combined with pixelated and time-reversed videos. However, higher engagement with the realistic audio–visual stimuli was not predictive of better song learning. Thus, although multimodality increased stimulus engagement and biologically relevant video content was more salient than colour and movement equivalent videos, the higher engagement with the realistic audio–visual stimuli did not lead to enhanced vocal learning. Whether the lack of three-dimensionality of a video tutor and/or the lack of meaningful social interaction make them less suitable for facilitating song learning than audio–visual exposure to a live tutor remains to be tested.

Reinke's Edema: Phonatory Mechanisms and Management Strategies

1997 ◽  
Vol 106 (7) ◽  
pp. 533-543 ◽  
Author(s):  
Steven M. Zeitels ◽  
Glenn W. Bunting ◽  
Robert E. Hillman ◽  
Traci Vaughn
Keyword(s):  
Lamina Propria ◽  
Fundamental Frequency ◽  
Vocal Fold ◽  
Management Strategies ◽  
Vocal Folds ◽  
Vocal Fold Vibration ◽  
Reinke’S Edema ◽  
Subglottal Pressure ◽  
Almost All ◽  
Superficial Lamina

Reinke's edema (RE) has been associated typically with smoking and sometimes with vocal abuse, but aspects of the pathophysiology of RE remain unclear. To gain new insights into phonatory mechanisms associated with RE pathophysiology, weused an integrated battery of objective vocal function tests to analyze 20 patients (19 women) who underwent phonomicrosurgical resection. Preoperative stroboscopic examinations demonstrated that the superficial lamina propria is distended primarily on the superior vocal fold surface. Acoustically, these individuals have an abnormally low average speaking fundamental frequency (123 Hz), and they generate abnormally high average subglottal pressures (9.7 cm H20). The presence of elevated aerodynamic driving pressures reflects difficulties in producing vocal fold vibration that are most likely the result of mass loading associated with RE, and possibly vocal hyperfunction. Furthermore, it is hypothesized that in the environment of chronic glottal mucositis secondary to smoking and reflux, the cephalad force on the vocal folds by the subglottal driving pressure contributes to the superior distention of the superficial lamina propria. Surgical reduction of the volume of the superficial lamina propria resulted in a significant elevation in fundamental frequency (154 Hz) and improvement in perturbation measures. In almost all instances, both the clinician and the patient perceived the voice as improved. However, these patients continued to generate elevated subglottal pressure (probably a sign of persistent hyperfunction) that was accompanied by visually observed supraglottal strain despite the normalsized vocal folds. This finding suggests that persistent hyperfunctional vocal behaviors may contribute to postsurgical RE recurrence if therapeutic strategies are not instituted to modify such behavior.

The visual pigments of the bottlenose dolphin (Tursiops truncatus)

1998 ◽  
Vol 15 (4) ◽  
pp. 643-651 ◽  
Author(s):  
JEFFRY I. FASICK ◽  
THOMAS W. CRONIN ◽  
DAVID M. HUNT ◽  
PHYLLIS R. ROBINSON
Keyword(s):  
Color Vision ◽  
Bottlenose Dolphin ◽  
Visual Pigments ◽  
Nucleotide Position ◽  
Long Wavelength ◽  
Terrestrial Mammals ◽  
Cone Opsin ◽  
Cone Pigments ◽  
The Common

To assess the dolphin's capacity for color vision and determine the absorption maxima of the dolphin visual pigments, we have cloned and expressed the dolphin opsin genes. On the basis of sequence homology with other mammalian opsins, a dolphin rod and long-wavelength sensitive (LWS) cone opsin cDNAs were identified. Both dolphin opsin cDNAs were expressed in mammalian COS-7 cells. The resulting proteins were reconstituted with the chromophore 11-cis-retinal resulting in functional pigments with absorption maxima (λmax) of 488 and 524 nm for the rod and cone pigments respectively. These λmax values are considerably blue shifted compared to those of many terrestrial mammals. Although the dolphin possesses a gene homologous to other mammalian short-wavelength sensitive (SWS) opsins, it is not expressed in vivo and has accumulated a number of deletions, including a frame-shift mutation at nucleotide position 31. The dolphin therefore lacks the common dichromatic form of color vision typical of most terrestrial mammals.

Evaluating the Influence of Targeted Air Flow on Sound Pressure Level and Closed Quotient

2021 ◽  
pp. 1-6
Author(s):  
Michael J. Hammer
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Air Flow ◽  
Vocal Folds ◽  
Pressure Level ◽  
Air Pressure ◽  
Steady Increase ◽  
Closed Quotient ◽  
Considerable Range

Purpose Measures of estimated subglottal air pressure and translaryngeal air flow enable the researcher or clinician to noninvasively assess aerodynamic features related to respiratory and phonatory function. Our goal was to examine the unique relationship between air flow with sound pressure level (SPL) during syllable production while attempting to hold fundamental frequency and subglottal air pressure relatively constant. Method We completed two studies. Study 1: During syllable production, resultant sound pressure level was measured under conditions of constant fundamental frequency and estimated subglottal air pressure while systematically varying translaryngeal air flow. Study 2: During syllable production, resultant sound pressure level and closed quotient (using laryngeal stroboscopy) were measured under conditions of constant fundamental frequency and estimated subglottal air pressure while systematically varying translaryngeal air flow. Results Study 1: Findings suggest a steady increase in sound pressure level with increases in air flow between 25 cc/s and 150 cc/s. Interestingly, relatively stable mean sound pressure level was maintained over a considerable range of air flow values between 225 and 450 cc/s, suggesting that air flow could be further increased without a marked loss of sound pressure level. Study 2: Findings suggest a systematic increase in mean sound pressure level as supraglottic activity subsided and as the closed quotient decreased from 0.80 to 0.58. Interestingly, sound pressure level was relatively stable as the closed quotient decreased from 0.58 to 0.35. Conclusions Our findings suggest that sound pressure level can be maintained over a considerable range of increasing translaryngeal air flow values and over a considerable range of decreasing closed quotient values. These results provide motivation for investigating the interaction between air flow, glottal closure, and sound pressure level among other measures of phonatory function, with important clinical implications for therapeutic approaches that emphasize increases in air flow and focus on reducing contact between the vocal folds.

Valuing your voice

2017 ◽  
Author(s):  
Peggy D. Bennett
Keyword(s):  
Physical Education ◽  
Sound Production ◽  
Vocal Folds ◽  
Good Argument ◽  
Vocal Production ◽  
Vocal Health ◽  
Large Classes ◽  
Music Ensembles ◽  
Speed Up ◽  
Good For

If you have ever contracted laryngitis, you know the value of your voice. You feel fine. You are not contagious. You have much to do. You cannot make a good argument for staying home. Yet teaching without a healthy voice can be hard, hard work. Our voice is our most precious instrument. Do we care for it as if that is true? These five suggestions can help you maintain a healthy voice. 1. Balance of breath and muscle. When vocal sound production is balanced with muscle and breath, we are generally using our voice properly. When more muscle than breath is used, a forced sound causes undue stress on our vocal folds, often resulting in a raspy sound. Support your voice with breath energy to help maintain healthy vocal production. 2. Hydration. Talking for lengthy amounts of time causes us to lose moisture through our breath. Don’t wait until you’re thirsty to drink water. Stay hydrated throughout the day. 3. Avoid touching your face. Our hands are often the germiest parts of our bodies. To maintain a healthy voice, avoid touch­ing your face, especially during cold and flu season. 4. Vary your vocal expression. Variety in pitch, pace, and vol­ume is good for our voices and good for our listeners. Vary the pitch of your voice by shifting between higher and lower tones. Speed up and slow down the pace of your speaking. Speak at louder and quieter volumes to help students listen. 5. Lift your voice. Speaking at the lower part of your vocal range, especially if you are projecting loudly to a group, can cause vocal difficulties similar to a callus on your vocal folds. For the health of your voice, lift it to a medium high range (say “mm- hm” as an agreement and stay at the “hm” level) and speak using plenty of breath energy. The louder we talk, the less students need or want to listen! Try speaking normally rather than “talking over” noisy students; they will learn to respond. In physical education, music ensembles, and other large classes, a habit of shout- speaking can develop and derail your vocal health.

scholarly journals A sciaenid swim bladder with long skinny fingers produces sound with an unusual frequency spectrum

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hin-Kiu Mok ◽  
Shih-Chia Wu ◽  
Soranuth Sirisuary ◽  
Michael L. Fine
Keyword(s):  
Frequency Spectrum ◽  
Fundamental Frequency ◽  
Pulse Repetition Rate ◽  
Sound Production ◽  
Swim Bladder ◽  
Low Frequencies ◽  
Pass Filter ◽  
Number Of Cycles ◽  
Almost All ◽  
High Pass

Abstract Swim bladders in sciaenid fishes function in hearing in some and sound production in almost all species. Sciaenid swim bladders vary from simple carrot-shaped to two-chambered to possessing various diverticula. Diverticula that terminate close to the ears improve hearing. Other unusual diverticula heading in a caudal direction have not been studied. The fresh-water Asian species Boesemania microlepis has an unusual swim bladder with a slightly restricted anterior region and 6 long-slender caudally-directed diverticula bilaterally. We hypothesized that these diverticula modify sound spectra. Evening advertisement calls consist of a series of multicycle tonal pulses, but the fundamental frequency and first several harmonics are missing or attenuated, and peak frequencies are high, varying between < 1–2 kHz. The fundamental frequency is reflected in the pulse repetition rate and in ripples on the frequency spectrum but not in the number of cycles within a pulse. We suggest that diverticula function as Helmholz absorbers turning the swim bladder into a high-pass filter responsible for the absence of low frequencies typically present in sciaenid calls. Further, we hypothesize that the multicycle pulses are driven by the stretched aponeuroses (flat tendons that connect the sonic muscles to the swim bladder) in this and other sciaenids.

Design of Apparatus for Studying Aerodynamics of Voice Production

2004 ◽  
Author(s):  
Michael Barry
Keyword(s):  
Flow Visualization ◽  
Vocal Fold ◽  
Sound Production ◽  
Vocal Tract ◽  
Vocal Folds ◽  
Flow Speed ◽  
Working Fluid ◽  
Voice Production ◽  
Experimental Apparatus ◽  
Glottal Flow

The design and testing of an experimental apparatus for in vitro study of phonatory aerodynamics (voice production) in humans is presented. The presentation includes not only the details of apparatus design, but flow visualization and Digital Particle Image Velocimetry (DPIV) measurements of the developing flow that occurs during the opening of the constriction from complete closure. The main features of the phonation process have long been understood. A proper combination of air flow from the lungs and of vocal fold tension initiates a vibration of the vocal folds, which in turn valves the airflow. The resulting periodic acceleration of the airstream through the glottis excites the acoustic modes of the vocal tract. It is further understood that the pressure gradient driving glottal flow is related to flow separation on the downstream side of the vocal folds. However, the details of this process and how it may contribute to effects such as aperiodicity of the voice and energy losses in voiced sound production are still not fully grasped. The experimental apparatus described in this paper is designed to address these issues. The apparatus itself consists of a scaled-up duct in which water flows through a constriction whose width is modulated by motion of the duct wall in a manner mimicking vocal fold vibration. Scaling the duct up 10 times and using water as the working fluid allows temporally and spatially resolved measurements of the dynamically similar flow velocity field using DPIV at video standard framing rates (15Hz). Dynamic similarity is ensured by matching the Reynolds number (based on glottal flow speed and glottis width) of 8000, and by varying the Strouhal number (based on vocal fold length, glottal flow speed, and a time scale characterizing the motion of the vocal folds) ranging from 0.01 to 0.1. The walls of the 28 cm × 28 cm test section and the vocal fold pieces are made of clear cast acrylic to allow optical access. The vocal fold pieces are 12.7 cm × 14 cm × 28 cm and are rectangular in shape, except for the surfaces which form the glottis, which are 6.35 cm radius half-circles. Dye injection slots are placed on the upstream side of both vocal field pieces to allow flow visualization. Prescribed motion of the vocal folds is provided by two linear stages. Linear bearings ensure smooth execution of the motion prescribed using a computer interface. Measurements described here use the Laser-Induced Fluorescence (LIF) flow visualization and DPIV techniques and are performed for two Strouhal numbers to assess the effect of opening time on the development of the glottal jet. These measurements are conducted on a plane oriented perpendicular to the glottis, at the duct midplane. LIF measurements use a 5W Argon ion laser to produce a light sheet, which illuminates the dye injected through a slot in each vocal fold piece. Two dye colors are used, one for each side. Quantitative information about the velocity and vorticity fields are obtained through DPIV measurements at the same location as the LIF measurements.

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