Laryngonaut Release Notes (Version 1.0.8) - January 18th, 2024:

This release involves two major new developments: (1) the beta version of the iOS version of Laryngonaut is ready for testing and (2) the app has been enhanced with simulation of vocal fold vibration and associated sound synthesis. Besides these, there are several other changes to note. Numerous enhancements have been made to the physiological correctness of the model, and the performance of the simulation has been improved. Fined-grained labels now appear when picking certain parts of the model to aid in anatomical feature identification. A "States of the Larynx" control panel has been implemented to allow the user to quickly move between postural configurations of the larynx that map onto a select range of phonetic-taxonomic categories, such as "breathy voice" and "glottal stop". The deformable-body physics simulation has been improved to reduce the chance of the epilaryngeal mucosa mesh self-intersecting. Please see below for further notes on technical issues and physiological correctness.

If you would like to be involved as an external tester of the iOS version, you can join the TestFlight for the iOS version of Laryngonaut by clicking here. Although it was not intended to be used as a desktop app, Laryngonaut works on macOS, but please take note of some of the technical issues below.

Please send any comments or questions to laryngonaut@gmail.com

Planned Features (@Version 1.0.8):

• An info panel that provides more details about selected structures

• Simulation of epilaryngeal vibration (ventricular and aryepiglottic vibration) and associated sound output

• An MR version of the app that let's you play with Laryngonaut using a VR headset

• Meshes to visualize muscles and connective tissues (i.e., ligaments and membranes)

  • Refinement of muscle structure, including subcompartments of the muscles like the cricothyroid (its pars oblique and pars recta) and the posterior cricoarytenoid muscle (its vertical and oblique portions)

  • Addition of surrounding structures such as the hyoid bone, trachea, and pharyngeal musculature

  • Simulation of laryngoscopic viewing

Known Technical Issues (@Version 1.0.8):

• On iPad and Mac, the scaling and placement of GUI components is incorrect the first time the app is started (if this happens, simply restarting the app seems to fix the issue)

  • On iPad and Mac, the text in the drop-down menu is badly scaled

• On Mac, two-finger pinch and rotate trackpad gestures can be used but they cannot be seamlessly blended together, requiring that the hand be removed from the trackpad prior to initiating a different gesture

• The minimum required Android version has been set to version 11 (API level 30)

• On older or lower-end phones the performance of the physics simulation may be quite slow, and there may be some glitches in the rendering of the GUI

• The sound synthesis can occasionally produce minor audio glitches, such as clicks or pops, and, typically under more extreme manipulation of the model, it can cause more unpleasant and sustained distortion

Known Issues Related to Physiological Correctness (@Version 1.0.8):

The physiological correctness of this version of Laryngonaut has been greatly improved with regard to the action of laryngeal muscles and their effect on laryngeal posturing in isolation and in combination with other muscles. This version should pose fewer difficulties if the intent is to use Laryngonaut as a teaching tool. A few issues still remain:

• • The sound synthesis can fail to detect whether the vocal folds have started or stopped vibrating, resulting in bouts of spurious voicing

  • There is no simulation of collision between the arytenoids and the cricoid cartilage (at the cricoarytenoid joint), which means that the movement of the arytenoids, while a decent approximation, is still not fully correct (e.g., under some combinations with other muscle activity levels, the PCA  will not cause enough expected abduction of the vocal folds)

  • The ventricular folds do not fully adduct even under extreme action of the TA muscle components (iTA and eTA)

  • Since there is no collision between the aryepiglottic folds and the epiglottis, the aryepiglottic folds do not appear to fully make contact with epiglottis during extreme epilaryngeal constriction

  • The CT muscle does not always have the effect of raising glottal f0 and the TA muscle debatably should raise f0 (especially at low levels of activity)

  • There is no representation of laryngeal height and its effects on sound output

Laryngonaut Release Notes (Version 1.0.5) - September 20th, 2023:

Thank you for using Laryngonaut! The app has been released for Android and is considered functional but future updates are still anticipated. In particular, there are some unavoidable physiological inaccuracies associated with the current implementation of the physics engine and model geometry (see details below). As such, caution should be exercised when using the app for teaching or learning purposes. 

Your feedback is highly valued; please feel free to send videos or screenshots documenting your experience or any comments to laryngonaut@gmail.com

 Planned Features (@Version 1.0.5):

• Labeling of fine-grained anatomical details (e.g., surface features of cartilages) when selecting structures

• An information panel that gives detailed descriptions of selected structures

• A complete set of laryngeal states or “Actions” and their mapping onto phonetic categories (along with IPA symbols)

• Meshes to visualize muscles and connective tissues (i.e., ligaments and membranes)

• Simulation of vibration of the vocal folds and epilaryngeal structures

• Sound synthesis reflecting the current state of the larynx

• Refinement of muscle structure, including subcompartments of the muscles like the cricothyroid (its pars oblique and pars recta) and the posterior cricoarytenoid muscle (its vertical and oblique portions)

• Addition of surrounding structures such as the hyoid bone, trachea, and pharyngeal musculature

• Simulation of laryngoscopic viewing

Known Technical Issues (@Version 1.0.5):

• On Android versions 10 and below, the app will crash immediately on loading. This bug will be fixed in the next release.

• On older or lower-end phones the performance of the physics simulation may be quite slow, and there may be some glitches in the rendering of the GUI. 

• There is a sporadic crash associated with activating the “parallel processing” feature in the “Options” panel.

• Pulling on the mucosa of the vocal folds or epilarynx can cause the meshes to become tangled and fail to return to their resting state. To fix use the "reset" button to restore the model to its original shape).

Known Issues Related to Physiological Correctness (@Version 1.0.5):

There are several issues with the physiological correctness of Laryngonaut resulting from the current developmental implementation of the model structures and the physics simulation. The muscles and connective tissues are not yet fully implemented, and there is currently no simulation of collision. The latter issue is especially important in accurate simulation of arytenoid motion. As a consequence, not all motions brought about by muscle actions are correct. The issues are as follows:

• The posterior cricoarytenoid (PCA) successfully abducts the vocal fold mucosa, but causes excessive posterior movement of the epilaryngeal mucosa and underlying cartilages and not enough lateral motion of the same structures, resulting in insufficient abduction of the laryngeal collar required for simulation of inspiration

• The internal thyroarytenoid (iTA) sometimes causes unwanted buckling and asymmetry of the vocal fold mucosa mesh and incorrectly causes abduction of the vocal folds, especially when combined with the external thyroarytenoid (eTA)

• The eTA muscle causes excessive adduction of the vocal folds

• The interarytenoid (IA) incorrectly causes abduction of the vocal folds

• The lateral cricoarytenoid (LCA) generates too much adduction of the cartilaginous glottis and incorrectly results in the cuneiform tubercles coming into contact

• Due to the above noted issue about vocal fold abduction under combination of iTA and eTA action, the vocal folds incorrectly abduct during epiglottal stop simulation

• Some combinations of muscle actions can cause the anterior portion of the epilarynx mucosa to clip through the thyroid cartilage or its posterior surface to clip into the lamina of the cricoid cartilage

• It is not possible to generate sufficient ventricular fold adduction to cause them to fully close overtop of the vocal folds, as in typical glottal stop production

• Due to of the way that the mucosa meshes are attached to the thyroid cartilage, extreme epilaryngeal constriction (through high levels of activation of the iTA and eTA) causes unwanted distortion of the lateral portions of the mucosa (in the region of the anterior-lateral walls of the piriform fossae)