Acoustics, Dynamics, and Controls Commons^™

Development Of Low-Cost Triaxial Force Sensor For Measurement Of Human-Exoskeleton Interaction Forces, Hamdan Khan Sarvathullah

All Theses

Contemporary research suggests that shear force is a major contributor to discomfort and pressure injury. However, the variation of shear forces during human-exoskeleton interaction dynamics is a highly unexplored field. The high cost of commercial triaxial force sensors may be a major factor in the notable lack of research in this field. Therefore, in this paper, we present a low-cost, 3D-printed triaxial force sensor designed specifically to measure the triaxial interaction forces between an exoskeleton and its user. The triaxial force sensor uses Carbon-Black/Silicone Rubber (CB/SR) strings to measure shear forces, whereas the normal force is measured with a Force …

Cure Sound Project: Study In Silence?, Quezia Abrao, Deeya Bhadresa, Elisa Castro, Fiona Coulbourne, Carlos Flores, Lizzeth Holguin, Lazarus Maldonado, Jeremy Mares, Andrew Martini, Nicole Matthews, Katherine Montero, Mariana Reyes, Jacob Rodriguez, Julieta Ruiz, Eliana Sanchez, Gabriela Varela

Posters - 2026

Difference in sound levels in study areas across campus can affect students’ ability to work and learn efficiently 1.

According to the WHO, safe sound levels are measured to be around 70dB 2. Some study areas on campus experience sound levels exceeding the safe threshold. Unsafe sound levels are considered to be at or above 85dB 3. These unsafe and excessive noise levels negatively affect a student’s ability to concentrate and work efficiently which correlates to a decrease in class performance, attention deficits, and stress 4.

This study aims to get a base-line measurement of dB levels in common study …

Guitar Amplifier Directivity, Rachel C. Edelman, Brian E. Anderson, Samuel D. Bellows, Timothy W. Leishman

Directivity

No abstract provided.

Acoustic Filter For Biopharmacy, Nicholas Rivet

Three Minute Thesis (3MT)

The design and development of a novel flow induced acoustically tuned “filterless” filter is proposed. The proposed research is on developing two or more prototypes that function as a cell retention device for perfusion cell cultures used in continuous manufacturing of monoclonal antibodies and recombinant proteins. This research will provide a non-invasive, cost-effective, flexible, and robust cell retention device for sustainable manufacturing of biologics.

Reliability Of An Extended Version Of The 3m™ Eargage Tool To Assess Earcanal Size And Assist Earplug Selection, Bastien Poissenot-Arrigoni, Laurence Martin, Alessia Negrini, Djamal Berbiche, Olivier Doutres, Franck Sgard

Études primaires

Objective: Evaluate the ability of an extended version of the 3 MTM Eargage to estimate the earcanal size and assess the likelihood that a particular earplug can fit an individual’s earcanal, ultimately serving as a tool for selecting earplugs in the field. Design: Earcanal morphology, assessed through earcanal earmolds scans, is compared to earcanal size assessed with the extended eargage (EE) via box plots and Pearson linear correlations coefficients. Relations between attenuation measured on participants (for 6 different earplugs) and their earcanal size assessed with the EE are established via comparison tests. Study sample: 121 participants exposed to occupational noise …

The Impact Of Hearing Aid User Speech On Environment Classification And Own Voice Listener Preferences, Robert Andrew Budinsky Iii

USF Tampa Graduate Theses and Dissertations

Hearing aids (HA) have improved over the past few decades with advanced signal processing, such as environment classification and background noise reduction, but are still limited by challenges related to when the user is speaking. These challenges include the potential interference a HA user’s voice has on device environment classification and the potential influence a HA has on own voice (OV) sound quality. However, the effects of OV on HA environment classification and signal processing are not well established, nor are the desired HA program settings regarding OV listening preferences. In this study, a combination of electroacoustic and behavioral methods …

Spatial Hearing In Simulated Reverberant Classroom Environments, Gabriel Seth Evan Weeldreyer

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Spatial hearing provides access to auditory spatial cues that promote speech perception in noisy listening situations. However, reverberation degrades auditory spatial cues and limits listeners’ ability to utilize these cues for segregating target speech from competing babble. Hence, spatial unmasking—an intelligibility benefit from a spatial separation between a target and masker—is reduced in reverberant environments as compared to free field. This work tests the hypothesis that interaural decorrelation, the result of increasing reverberation, will broaden the perceived auditory source width with a cascading effect of reduced auditory spatial acuity and subsequently poorer spatial unmasking. To understand the perceptual consequences of …

An Impedance Tube Technique For Estimating The Insertion Loss Of Earplugs, K. Carillo, O. Doutres, F. Sgard

Études primaires

This paper proposes a quick and straightforward technique for estimating the insertion loss (IL) of earplugs measured on an acoustical test fixture (ATF) using a commercial impedance tube. In this method, the earplug's acoustic properties (i.e., its transmission loss and the reflection coefficient of its medial surface) are determined from its transfer matrix measured using the three-microphones impedance tube method modified here for the current application. The IL is then estimated using a one-dimensional analytical model of open and occluded earcanals based on the wavefield decomposition theory. The method is evaluated numerically and experimentally from 50 Hz to 6.5 kHz. …

On The Area-Averaged Effective Sound Absorption Coefficient Of Porous Materials Excited By A Monopole, Franck Sgard, Noureddine Atalla, Olivier Robin, Alain Berry

Études primaires

The area-averaged effective sound absorption coefficient (SAC) of a rigid-backed homogeneous porous material subjected to a monopole excitation is calculated as the absorbed-to-incident sound power ratio. Using Allard's model to describe the sound propagation above the porous material, an analytical model for this power-based SAC is proposed and proves to give a good approximation of the sound absorption performance under monopole excitation of sufficiently large areas of material. The impact of factors on the power-based SAC, such as monopole height, material radial dimension used to calculate the sound powers, and material properties is discussed. The power-based SAC frequency-dependent behavior is …

Measurement Of The Local Static Mechanical Pressure Of Earplugs, Luiz G.C. Melo, Ahmed S. Dalaq, Franck Sgard, Olivier Doutres, Laurianne Legroux, Eric Wagnac

Études primaires

Earplugs are used in various critical industrial sectors, such as construction, aviation, military and defense, transportation, and healthcare. However, they present inherent drawbacks, notably discomfort that can lead to inconsistent and incorrect use, thereby leaving a significant proportion of workers vulnerable to irreversible hearing damage, ranging from tinnitus to deafness. This discomfort is closely linked to a physical parameter known as static mechanical pressure (SMP), representing the pressure exerted by earplugs on the earcanal walls. Determining the SMP is crucial for developing earplugs that prioritize comfort. However, experimental studies in this area are scarce and there is no experimental set-up …

Développement D’Un Système De Mesure Pour La Caractérisation Des Traitements Absorbants En Laboratoire, Alain Berry, Olivier Robin, Thomas Dupont, Franck Sgard

Rapports de recherche scientifique

Le bruit constitue une préoccupation de plus en plus importante et généralisée dans le monde. Selon l’Organisation mondiale de la Santé, environ une personne sur quatre dans le monde souffrira de déficience auditive à des degrés divers d’ici à 2050. Dans de nombreux pays et régions du globe, le bruit représente le second facteur environnemental provoquant le plus de dommages sanitaires, et ce derrière la pollution atmosphérique. Sur un volet cognitif ou perceptif, le bruit environnemental peut par exemple perturber le sommeil et gêner l’apprentissage en milieu scolaire. Dans un milieu de travail, il peut perturber la bonne compréhension/perception de …

Trumpet Directivity From A Rotating Semicircular Array, Samuel D. Bellows, Joseph E. Avila, Timothy W. Leishman

Directivity

The directivity function of a played musical instrument describes the angular dependence of its acoustic radiation and diffraction about the instrument, musician, and musician’s chair. Directivity influences sound in rehearsal, performance, and recording environments and signals in audio systems. Because high-resolution, spherically comprehensive measurements of played musical instruments have been unavailable in the past, the authors have undertaken research to produce and share such data for studies of musical instruments, simulations of acoustical environments, optimizations of microphone placements, and other applications. The authors acquired the data from repeated chromatic scales produced by a trumpet played at mezzo-forte in an anechoic …

A Proof Of Concept For Detection Of Palato-Lingual Contact Without Intraoral Electrodes In A Human Participant, Amitava Biswas

Master's Theses

The author of this thesis conceived and investigated an unexpected electrical signal that may not be noticed during regular electroglottography (EGG) when electrodes are conventionally placed on the anterior surface of the throat. It appears that there is a measurable electrical signal from the EGG equipment when electrodes are placed over the frontal cheek (belly of zygomatic muscle), and the tongue is elevated to contact the hard palate, or the tongue is lowered to break the contact. Therefore, this phenomenon is designated as unconventional electroglottography (UEGG, Dr. Steven Cloud, private communication, July 17, 2022).

Two distinctive patterns of waveforms were …

Gamelan Gong Directivity Dataset, Samuel D. Bellows, Dallin T. Harwood, Kent L. Gee, Micah R. Shepherd

Directivity

No abstract provided.

Passive Earplug Including Helmholtz Resonators Arranged In Series To Achieve Broadband Near Zero Occlusion Effect At Low Frequencies, Kevin Carillo, Franck Sgard, Olivier Dazel, Olivier Doutres

Études primaires

The use of passive earplugs is often associated with the occlusion effect: a phenomenon described as the increased auditory perception of one's own physiological noise at low frequencies. As a notable acoustic discomfort, the occlusion effect penalizes the use and the efficiency of earplugs. This phenomenon is objectively characterized by the increase in sound pressure level in the occluded ear canal compared to the open ear canal. Taking inspiration from acoustic metamaterials, a new design of a three-dimensional printed “meta-earplug,” made of four Helmholtz resonators arranged in series, is proposed for achieving near zero objective occlusion effect measured on artificial …

Pressure Induced By Roll-Down Foam-Earplugs On Earcanal, Ahmed Dalaq, Luiz Melo, Franck Sgard, Olivier Doutres, Éric Wagnac

Études primaires

Physical discomfort of earplug is a common complaint, so much so it jeopardizes the health and safety of workers, resulting in frequent noncompliance to proper wearing of earplugs. A pressing need thus arises to understand the underlying mechanics for the interaction of earplugs with earcanal walls. An idealized cylindrical geometry of earcanal is first treated with computational and analytical modeling to predict the pressure induced by roll-down cylindrical PVC foam earplugs. In order to predict representative pressure values and distribution, we estimated the hyperelastic properties of foam-based earplugs and characterized their behavior using a stent testing machine (J-Crimp^TM machine) …

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

This directivity data set for a KEMAR head head-and-torso simulator (HATS) includes head orientations in 14 directions in 5° steps starting from 0° to 40° and then in 10° steps from 40° to 90°. The full spherical measurements followed at an a = 0.97 m radius with the mouth aperture at the spherical center. The sampling density and distribution followed the AES 5° dual-equiangular sampling standard, omitting the south pole (θ = 180°). Thus, each spherical directivity assessment included 36 polar-angle θ samples and 72 azimuthal-angle ϕ samples. The presented data include 22 1/3-octave bands, ranging from 80 Hz …

Développement D'Une Méthode De Mesure De L'Exposition Sonore Effective Intraauriculaire Pour Une Utilisation En Milieu De Travail, Hugues Nélisse, Fabien Bonnet, Marcos Nogarolli, Jérémie Voix

Rapports de recherche scientifique

De nombreux travailleurs sont exposés quotidiennement à des niveaux de bruit susceptibles d'endommager leur audition. De ce fait, la mesure de l'exposition sonore est essentielle afin d'identifier et d’évaluer des solutions correctives pour protéger adéquatement les travailleurs. Cependant, les méthodes et les technologies de mesure actuelles ne permettent généralement pas de déterminer avec précision l'exposition au bruit subie par un individu sur son lieu de travail. La dosimétrie intraauriculaire est une solution prometteuse pour pallier un certain nombre de problèmes liés aux méthodes de mesure conventionnelles, mais cette méthodologie est fragilisée de trois façons : 1) l'exposition sonore mesurée dans …

Étude De L’Applicabilité De Haut-Parleurs Paramétriques Au Développement De Nouveaux Concepts D’Alarmes De Recul, Olivier Robin, Alain Berry, Hugues Nélisse

Rapports de recherche scientifique

L’utilisation d’alarmes de recul est obligatoire sur une majorité de véhicules lourds et reste un moyen largement utilisé pour prévenir et alerter les personnes œuvrant à proximité de ces véhicules. Des études antérieures, réalisées par l’IRSST, ont montré les limites d’efficacité des alarmes utilisées en milieu de travail pour minimiser le risque à la sécurité des travailleurs. De plus, les alarmes de recul, par le son de niveau élevé et très typé qu’elles produisent, sont régulièrement une source de nuisance importante pour les travailleurs, et aussi pour les riverains. Ces problèmes de gêne et de perception sonore pour les travailleurs …

Mise Au Point D’Une Méthode De Mesure Objective De L’Effet D’Occlusion Basée Sur La Voix, Hugues Nélisse, Hugo Saint-Gaudens, Franck Sgard, Olivier Doutres

Rapports de recherche scientifique

Lors de l’utilisation de protecteurs auditifs ou de prothèses auditives, le fait d’obstruer le canal auditif peut engendrer un effet indésirable et désagréable, appelé « effet d’occlusion », qui se manifeste notamment par la sensation que notre propre voix sonne différemment, avec de basses fréquences amplifiées, qu’elle est distordue. L’effet d’occlusion est souvent considéré comme une source d’inconfort qui entraîne parfois les utilisateurs de protecteurs ou de prothèses à mal les utiliser ou encore à simplement les retirer. Dans le cas des travailleurs, par exemple, le retrait des protecteurs auditifs peut les exposer à des niveaux de bruits potentiellement dangereux, …

Assessing The Comfort Of Earplugs: Development And Validation Of The French Version Of The Coprod Questionnaire, Jonathan Terroir, Nellie Perrin, Pascal Wild, Olivier Doutres, Franck Sgard, Chantal Gauvin, Alessia Negrini

Études primaires

Earplugs are a common form of protection for workers exposed to hazardous noise levels. Their comfort directly impacts the effective protection by influencing their consistent and correct use. Nevertheless, comfort definition may vary according to the studies. Thus, a previous review of the literature has shown that to improve our understanding of perceived comfort and to reduce measurement variability, it is advisable to consider comfort through a multidimensional construct (physical, acoustical, functional and psychological). On this basis, the COPROD (COnfort des PROtections auDitives/COmfort of hearing PROtection Devices) questionnaire was developed. It is intended for people working in noisy environments. Nine …

Principle Of An Acoustical Method For Estimating The Centroid Position Of The Earcanal Wall Normal Velocity Induced By Bone-Conducted Stimulation: Numerical Evaluation, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The occlusion effect is commonly experienced as the altered perception of one’s own physiological noise when the earcanal entrance is blocked. Objectively, this phenomenon corresponds to an acoustic pressure increase in the occluded earcanal. The occlusion effect originates from the earcanal wall normal vibration and depends on the spatial distribution of the latter. At low frequencies, this spatial distribution can be characterized by the position of its centroid along the earcanal middle axis. This paper describes the principle of an acoustical method for estimating this centroid position at low frequencies. The proposed method consists in measuring the eardrum acoustic pressure …

Numerical Investigation Of The Earplug Contribution To The Low-Frequency Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The use of earplugs is commonly associated with an increased perception of the bone-conducted part of one's own physiological noise. This phenomenon is referred to as occlusion effect and is most prominent at low frequencies. Several factors influence the occlusion effect, such as the ear anatomy; the bone-conducted stimulation; and the type of occlusion device and its fit, insertion depth, and material properties. The latter factor is of great interest to potentially reduce the occlusion effect of passive earplugs. This paper investigates the mechanism(s) of contribution of earplugs to the objective occlusion effect. A two-dimensional axi-symmetric finite element model of …

On The Removal Of The Open Earcanal High-Pass Filter Effect Due To Its Occlusion: A Bone-Conduction Occlusion Effect Theory, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The occlusion effect is commonly experienced by in-ear device wearers as an increased loudness sensation of bone-conducted low frequency sounds. A widespread theory proposed by Tonndorf and based on a simplified electro-acoustic model describes the phenomenon as the removal of the open earcanal high-pass filter effect due to a perfect or partial occlusion. However, this filter has not been clearly defined and several ambiguities remain. Revisiting the model, a second order high-pass filter effect for the volume velocity transferred between the earcanal wall and the eardrum is highlighted. This filter remains for partial occlusion but vanishes for perfect occlusion. In …

Simulation Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation Using A Three-Dimensional Finite-Element Model Of A Human Head, Huiyang Xu, Franck Sgard, Kévin Carillo, Éric Wagnac, Jacques De Guise

Études primaires

The occlusion effect (OE) refers to the phenomenon that more bone-conducted physiological sounds are transmitted into the earcanal when it is blocked and may cause discomfort on users of hearing protection devices. Models have been proposed to study the OE as they can help understand the physical mechanisms and can be used to evaluate the individual contribution on the OE of the factors that may affect it (i.e., occlusion device, ear anatomy, and stimulation). The existing finite element models developed to study the OE are limited by their truncated ear geometries. In order to progress in the understanding of the …

Effect Of Hearing And Head Protection On The Localization Of Tonal And Broadband Reverse Alarms, Chantal Laroche, Christian Giguère, Véronique Vaillancourt, Claudia Marleau, Marie-France Cadieux, Karina Laprise-Girard, Emily Gula, Véronique Carroll, Manuelle Bibeau, Hugues Nélisse

Études primaires

Objective

This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise.

Background

Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization.

Method

Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) …

Understanding Of Aerosol Transmission Of Covid 19 In Indoor Environments, Adama Barro, Cathal O'Toole, Jacob S. Lopez, Matthew Quinones, Sherene Moore

Publications and Research

Our reason for discussing severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) or 2019 novel corona virus (Covid-19), is to understand its aerosol transmission characteristics in indoor spaces and to mitigate further spread of this disease by designing a new HVAC system. The problem that we are tackling is the spread of covid-19 droplets through aerosol transmission by looking at potential engineering solutions to the existing HVAC systems. The purpose is to eradicate the spread of the COVID-19 by testing indoor spaces in an effort to understand the effectiveness of ventilation controls. We believe that scientists and engineers have not …

Semi Open Partitions: A Defense Strategy For Airborne Disease, Kerrie Marshall, Arik Palileo, Eric A. Schiff

SyracuseCoE

This brief summarizes research on two measures that reduce the risk of transmitting COVID-19 from an infected person to a virus-free individual. Semi-partitioned spaces can reduce airborne disease transmission when combined with a proper ventilation flow pattern in a room. With advanced displacement ventilation risk can be reduced by at least 4 times.

Theoretical Investigation Of The Low Frequency Fundamental Mechanism Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard

Études primaires

The objective occlusion effect induced by bone-conducted stimulation refers to the low frequency acoustic pressure increase that results from occluding the ear canal opening. This phenomenon is commonly interpreted as follows: the bone-conducted sound “leaks” through the earcanal opening and is “trapped” by the occlusion device. This instinctive interpretation misrepresents the fundamental mechanism of the occlusion effect related to the earcanal impedance increase and already highlighted by existing electro-acoustic models. However, these models simplify the earcanal wall vibration (i.e., the origin of the phenomenon) to a volume velocity source which, in the authors' opinion, (i) hinders an exhaustive comprehension of …

Conception D’Oreilles Artificielles Réalistes Dédiées À L’Étude Du Confort Acoustique Et Physique Des Protecteurs Auditifs Intra-Auriculaires, Simon Benacchio, Olivier Doutres, Éric Wagnac, Franck Sgard

Rapports de recherche scientifique

Au Québec, environ 360 000 travailleurs sont exposés quotidiennement à des niveaux de bruit susceptibles d’engendrer des problèmes d’audition. Les protecteurs auditifs individuels sont souvent utilisés pour pallier ce problème. Cependant, l’inconfort lié à l'utilisation de ces protecteurs limite la durée du port et donc l'efficacité de la protection. Le développement d'outils de conception acoustique minimisant les sources d’inconforts auditifs et physiques de ces protecteurs tout en assurant une atténuation adéquate constitue le contexte de cette recherche.

La présente étude se concentre sur deux indicateurs du confort associés au port des bouchons d’oreille : l’atténuation et l’effet d’occlusion. L’atténuation quantifie …