Acoustic Assessment Research Articles

Update of Vocal Fold Shortening With Retrodisplacement of Anterior Commissure for Voice Feminization.

To assess the efficacy and long-term durability of the enhanced technique of Type II Vocal Fold Shortening and Retrodisplacement of the Anterior Commissure (VFSRAC) for voice feminization compared with the preceding Type I method. A retrospective analysis encompassed 506 patients drawn from a cohort of 1025 MtF transgender women who underwent VFSRAC between 2003 and 2021. The study period included cases from 2015 to 2021, during which the Type II update technique was implemented, involving a modification to the suture technique. Subjective and perceptual evaluations, aerodynamic and acoustic assessments, real-time pitch analysis, and videostroboscopic reviews were conducted pre- and postoperatively in the MtF transgender women cohort. Comparative statistical analyses were performed to discern differences between the earlier Type I method (2003-2014) and the more recent Type II method (2015-2021). The preoperative mean speech fundamental frequency (sF0) for Type II VFSRAC was 134.5 Hz. Postoperatively, the mean sF0 increased to 196.7 Hz, 212.3 Hz, and 207.5 Hz at 3 months, 6 months, and beyond 1 year, respectively, exceeding outcomes observed with the Type I method. Postoperative subjective and objective assessments indicated an augmentation in voice femininity. Acoustic and aerodynamic indices were within the normal range, and the regularity of the vocal fold mucosal wave was preserved within normal parameters. These results suggest that patients achieved a natural phonation pattern after surgery. The application of our updated type II VFSRAC has demonstrated feasibility and consistently yielded favorable results for individuals desiring a naturally feminine voice. 3 Laryngoscope, 134:5054-5061, 2024.

Acoustical features as knee health biomarkers: A critical analysis

Acoustical knee health assessment has long promised an alternative to clinically available medical imaging tools, but this modality has yet to be adopted in medical practice. The field is currently led by machine learning models processing acoustical features, which have presented promising diagnostic performances. However, these methods overlook the intricate multi-source nature of audio signals and the underlying mechanisms at play. By addressing this critical gap, the present paper introduces a novel causal framework for validating knee acoustical features. We argue that current machine learning methodologies for acoustical knee diagnosis lack the required assurances and thus cannot be used to classify acoustic features as biomarkers. Our framework establishes a set of essential theoretical guarantees necessary to validate this claim. We apply our methodology to three real-world experiments investigating the effect of researchers’ expectations, the experimental protocol, and the wearable employed sensor. We reveal latent issues such as underlying shortcut learning and performance inflation. This study is the first independent result reproduction study in acoustical knee health evaluation. We conclude by offering actionable insights that address key limitations, providing valuable guidance for future research in knee health acoustics.

Experimental Investigation and Validation of Measured Wind Turbine Noise Characteristics using Standardized Technology

This paper aims in affirming the accuracy and consistency of acoustic noise assessment at an experimental and Grid Connected wind turbine. The experimental turbine is a three-bladed, upwind turbine located in the Tuticorin District of Tamil Nadu State in India. The measurement campaign was carried out during the noise measurement equipment by Brüel & Kjær (B&K) PULSE Wind Turbine Sound Power Determination system strictly in accordance with the IEC 61400-11 2012-11 AMDI 2018 Ed.3.1. The Experimental study deals in the measurement of total noise emitted from various wind turbine component and sub-systems, when the turbine is in ON condition. The background noise was obtained while the turbine is in OFF condition. The measurement data was obtained as per the above referred standards for wind speeds ranging from 7m/s to 13.5 m/s at 50m hub height. The measurement was also obtained simultaneously at 10m height above ground level for the wind speed ranging 6m/s to 8m/s during the windy season of September 2022. The measurement data both at turbine hub height and 10m level were obtained at the same atmospheric condition 26o C and 0.996atm and in a down wind direction. The other parameters like Aweighted sound pressure level, 1/3 octave band spectrum, electric power, and wind speed were also measured at both hub heights at 10m level. The measured parameters were compared with the PULSE Software output and in the process; it is concluded that the noise characteristic of the experimental wind turbine is less than 3dB at a distance of 66m in the down wind direction from the test turbine. The measured results were also validated from the PULSE software and the results show a close match.

Real and Virtual Lecture Rooms: Validation of a Virtual Reality System for the Perceptual Assessment of Room Acoustical Quality

Enhancing the acoustical quality in learning environments is necessary, especially for hearing aid (HA) users. When in-field evaluations cannot be performed, virtual reality (VR) can be adopted for acoustical quality assessments of existing and new buildings, contributing to the acquisition of subjective impressions in lab settings. To ensure an accurate spatial reproduction of the sound field in VR for HA users, multi-speaker-based systems can be employed to auralize a given environment. However, most systems require a lot of effort due to cost, size, and construction. This work deals with the validation of a VR-system based on a 16-speaker-array synced with a VR headset, arranged to be easily replicated in small non-anechoic spaces and suitable for HA users. Both objective and subjective validations are performed against a real university lecture room of 800 m3 and with 2.3 s of reverberation time at mid-frequencies. Comparisons of binaural and monoaural room acoustic parameters are performed between measurements in the real lecture room and its lab reproduction. To validate the audiovisual experience, 32 normal-hearing subjects were administered the Igroup Presence Questionnaire (IPQ) on the overall sense of perceived presence. The outcomes confirm that the system is a promising and feasible tool to predict the perceived acoustical quality of a room.

Acoustic Target Strength Measurement of Larmichthys crocea Based on the Kirchhoff-Ray Mode Model

Larmichthys crocea (L. crocea) is an economically important fish species mainly distributed off the coast of China. In this study, 11 L. crocea samples of different body lengths were collected from aquaculture cages in the East China Sea to measure the acoustic target strength (TS). Using the Kirchhoff-Ray mode (KRM) model, the directional TS of L. crocea was measured at frequencies of 70 kHz, 120 kHz, and 200 kHz. Furthermore, the relationships between TS and body length were determined using the least squares method and the standard b20 equation. The results showed that the TS of L. crocea varied with tilt angle, frequency, and body length. For tilt angles ranging from (−5°, 15°), the equation for fitting TS and body length using the least squares method were TS = 32.99·log10L − 87.36 (70 kHz), TS = 33.26·log10L − 87.77 (120 kHz), and TS = 39.46·log10L − 95.51 (200 kHz). They were expressed in the standard b20 equation as TS = 20·log10L − 71.16 (70 kHz), TS = 20·log10L − 71.23 (120 kHz), and TS = 20·log10L − 71.24 (200 kHz). For tilt angles ranging from (0°, 10°), the equation for fitting TS and body length using the least squares method is TS = 28.69·log10L − 81.71 (70 kHz), TS = 32.30·log10L − 86.44 (120 kHz), and TS = 45.87·log10L − 103.73 (200 kHz). They were expressed in the standard b20 equation as TS = 20·log10L − 70.88 (70 kHz), TS = 20·log10L − 71.10 (120 kHz), and TS = 20·log10L − 71.48 (200 kHz). Moreover, the 18–300 kHz spectral curve showed a decreasing trend in the frequency range from 18 kHz to 30 kHz, while maintaining relatively stable fluctuations in the other frequency ranges. These findings offer a comprehensive understanding of the scattering characteristics of L. crocea and provide a reliable reference of TS for the fishery acoustic assessment of L. crocea.

Ambient noise criteria framework for future environmental noise mitigation targets in Singapore

This study aims to establish a framework for outlining future noise mitigation strategies tailored to the unique context of Singapore and evaluates potential precautions. Singapore, as a city-state, is known as a 'city in a garden,' situated in the typically tropical climate. By incorporating a comparative analysis of noise criteria from local guidelines across countries from Europe, America, and Asia, the study aims to place Singapore's acoustic limits within an international context. This comparison, enhanced with the World Health Organization's health and well-being standards, seeks to establish a comprehensive framework for acoustical design assessment in residential, office, and educational buildings targeting resting and cognitive functions. In conclusion, starting from a global perspective, the study points to the importance of focusing on the local context and acknowledging the challenges and benefits that the context brings for acoustical comfort. The study discusses the importance of context and content in crafting acoustical design criteria, considering the impact of biophilic design and active noise cancellation windows to achieve adaptive acoustic comfort in Singapore's built environment.

Acoustic assessment of pavement structural health

Determining the in-situ asset condition of a pavement is necessary to programme pavement renewal and life extension work. Concrete pavements can develop different forms of structural faults including variable types of cracking, spalling, slab rocking, corrosion of reinforcement and softening of subgrade. This paper reports on work designed to detect deterioration before it manifests at the surface, in the form of defects that would only then have been picked up through visual inspection. The approach involves non-destructive, real-time monitoring with a Close Proximity (CPX) trailer, utilising both microphones and a tri-axial accelerometer. Dependent on its condition, the concrete pavement and subgrade will respond differently to traffic induced acoustic noise and vibration from the tyres. The variability in response is analysed using specialist spectral and acoustic signal processing techniques, to detect any internal and external cracks in the pavement, as well as to assess the condition of the subgrade. By characterising the pavement into uncracked, lightly cracked and heavily cracked areas, the collected data is used to map crack locations and their severity. Repeated surveys will allow temporal changes to be monitored and its rate of decay to be predicted, enabling the scheduling of renewal and life extension to be optimised.

Psychoacoustic assessment of automotive fan-systems

In the automotive industry, electrification trends worldwide are inducing an increase of noise sources emergences. This reinforces the acoustic assessment metrics and thresholds set by stakeholders to ensure acoustic comfort of car passengers and passersby. The main acoustic indicator, the overall Sound Pressure Level, is not relevant enough to depict pedestrian annoyance during exposure to fan-system noises. Currently, psychoacoustic assessment of these products is not systematic as the psychoacoustic metrics taken separately are not sufficient for sound quality ranking. In order to address this weakness, studies were performed by Valeo based on fan-system noise jury evaluations. It aims at providing a preference model consisting of an equation which combines several psychoacoustic metrics to assess fan-system noise annoyance; keeping in mind that Loudness -or overall SPL- high levels could mask underlying annoyances biasing its assessment. In a first step, the correlation between Overall SPL, Loudness and aeraulic power is highlighted based on standard benchmark test database. In a second step, since tonal noises affect the perceived annoyance, additional tonal metrics are analyzed versus Loudness, or acoustic classes. Tonality especially is then compared to other tonal criteria, before potential assessment of a preference model equation.

A causal model for acoustic assessment of informal learning environments

Irrelevant and intelligible speeches are the most effective distractive noise sources in open-plan environments. They are inevitable in informal learning environments as group assignments are very common. Informal learning can be defined as any additional learning activity that takes place outside the classroom and is conducted individually and collaboratively on campus. This study will examine the impact of sound-absorbing materials on students' attention in informal learning environments in a causal manner. To examine the effect of materials, 3D models will be designed by changing the sound-absorbing materials, using reverberation time as a reference metric by applying the auralization process. The control and treatment models will be provided. The statistical significance of the impacts will be investigated using pairwise correlations, ANOVA, and multivariate regression methods.

Adaptive stepsize forward–backward pursuit and acoustic emission-based health state assessment of high-speed train bearings

Compressed sensing (CS) is a promising tool for data compression reconstruction. However, fault diagnosis methods for high-speed train bearings based on CS and acoustic emission (AE) technologies have not been reported yet. Notably, the accuracy and speed of CS two-stage reconstruction methods are affected and restricted by prior initial conditions. Therefore, this article proposes adaptive dynamic thresholds applicable to adaptive stepsize forward–backward pursuit (ASFBP), and bearing health state assessment method. First, the adaptive dynamic thresholds for atom selection and deletion are constructed based on the residual feedback mechanism and the atom quality distribution law, which enables ASFBP to realize high-precision rapid reconstruction of signal without any atom priori initial conditions. Second, the initial dictionary length is improved based on the AE hit characteristics. Furthermore, a damage state comprehensive evaluation index (DSCEI) is established using principal component analysis based on AE time-domain hit parameters and compression-domain energy parameter. Compared with the kurtosis index and permutation entropy index, the DSCEI demonstrates better monotonicity and stability in the quantitative evaluation of high-speed train bearing condition. Finally, the validity and stability of the method are verified by testing under complex test conditions resembling actual high-speed train lines, providing valuable insights for the CS-based data-driven bearing fault diagnosis.

An innovative approach to automate BIM data retrieval and processing for building acoustic comfort calculations based on the IFC standard

Nowadays, there is a growing demand for deep renovation projects aimed at improving the energy efficiency of buildings while enhancing indoor comfort conditions for the inhabitants, both thermal and acoustic. To design effective renovation strategies, technicians need to know the current state of the building to propose acoustic or only thermal improvements. However, evaluating indoor acoustic comfort requires time-consuming and tedious calculations, which can be prone to errors when handled manually. While Building Information Modelling (BIM) can facilitate this process by leveraging the extensive contained data and offering the potential to automate these processes, such automation is not yet widespread. Typically, only geometric data is retrieved automatically from BIM models in acoustic software, while acoustic parameters must be provided manually. This paper addresses these challenges by introducing a novel approach that integrates automated data extraction from BIM with acoustic simulation tools. Specifically, an Extract, Transform and Load (ETL) solution was designed to automatically retrieve both geometric and acoustic data for an Acoustic Comfort tool, which calculates an estimation of indoor acoustic comfort, from an Industry Foundation Classes (IFC). This approach was tested in a demonstration case located in Spain, showing a significant reduction in processing time and increased accuracy compared to traditional methods of manually extracting data from BIM for acoustic assessment. This research represents a significant advance in acoustic simulations by integrating IFC data with automated processing, improving accuracy and offering practical advantages for developing more efficient and reliable BIM-based applications, thus supporting the design of deep renovation projects.

Acoustic Target Strengths and Swimbladder Morphology of Chub Mackerel Scomber japonicus in the Northwest Pacific Ocean

The Northwest Pacific chub mackerel (Scomber japonicus) is one of the most productive, economically important fishery resources worldwide. Accurately assessing this species and ensuring adherence to total allowable catch limits are crucial owing to fluctuations in their abundance and distribution. Acoustic target strength measurements of S. japonicus were conducted at 38, 70, and 120 kHz using a split-beam echosounder of individuals from nine size groups (mean fork length, 10.8–28.3 cm) swimming freely in a net cage within a seawater tank. An underwater camera was utilized to simultaneously measure swimming angle. Least-squares regression analysis revealed that when the slope was constrained to 20, as per the generally applicable morphometric equation, the resulting values for the constant term (b20) were −67.7, −66.6, and −67.3 dB at 38, 70, and 120 kHz, respectively. S. japonicus mean swimming angle across the groups was −10.5–9.6° (standard deviation [SD], 16.3–33.3°). Furthermore, the ratio of swimbladder height to swimbladder length, the ratio of swimbladder length to fork length, and the tilt angle of the swimbladder (mean ± SD) were 0.191 ± 0.060, 0.245 ± 0.055, and 9.6 ± 3.0°, respectively. These results can be used for the acoustic stock assessment of S. japonicus in the Northwest Pacific Ocean.

Investigations on Target Strength Estimation Methods: A Case Study of Chub Mackerel (Scomber japonicus) in the Northwest Pacific Ocean

Target strength (TS) is an acoustic property of individual marine organisms and a critical factor in acoustic resource assessments. However, previous studies have primarily focused on measuring TS at narrowband, typical frequencies, which cannot meet the requirements of broadband acoustic technology research. Additionally, for marine fish, conducting in situ TS measurements is challenging due to environmental constraints. Rapidly freezing and preserving fish samples for transfer to the laboratory is a common method currently used. However, the impact of freezing preservation during transportation on the swimbladder morphology and TS of swimbladder-bearing fish remains unclear. This study investigated the differences in swimbladder morphology and TS of Chub mackerel (Scomber japonicus) before and after freezing. Then, we compared different TS measurement methods through ex situ TS measurements (45–90 kHz, 160–260 kHz) and the Kirchhoff-ray mode model (KRM) simulations (1–300 kHz) and studied the broadband scattering characteristics of Chub mackerel based on the KRM model. The results showed that the morphology of the swimbladder was reduced after freezing, with significant changes in swimbladder height and volume. However, the trends of TS were not consistent and the changes were small. The difference between the KRM model and ex situ measurements was −0.38 ± 1.84 dB, indicating good applicability of the KRM. Based on the KRM results, the TS exhibited significant directivity, with fluctuations gradually decreasing and stabilizing as frequency increased. In the broadband mode, the relationship between TS and body length (L) of Chub mackerel was TS = 20log(L) − 66.76 (30 > L/λ >10). This study could provide a reference for acoustic resource estimation and species identification of Chub mackerel in the Northwest Pacific Ocean.

Unveiling the Acoustic Signature of Collichthys lucidus: Insights from X-ray Morphometry-Informed Acoustic Modeling and Empirical Analysis

Collichthys lucidus is an important small-scale economic fish species in the Yangtze River Estuary. To improve the accuracy of acoustic stock assessments for C. lucidus, it is necessary to accurately measure its target strength (TS). This study obtained precise morphological parameters of C. lucidus through X-ray scanning and established a Kirchhoff ray mode (KRM) model to simulate the changes in TS of the fish body and swimbladder at different acoustic frequencies and pitch angles. At the same time, the TS was measured using the tethered method to analyze and compare the broadband scattering characteristics obtained from both methods. An empirical formula of C. lucidus relating TS to body length at two conventional frequencies was established using the least squares method. The results show that the C. lucidus TS changes, with body length ranging from 10.91 to 16.61 cm, are significantly influenced by the pitch angle at 70 kHz and 200 kHz frequencies, and the fluctuation of TS for both the fish body and swimbladder increases with the rise in frequency. The broadband TS values estimated by the KRM model and measured by the tethered method fluctuate within in the ranges from −45 dB to −55 dB and −40 dB to −55 dB, respectively. The TS of C. lucidus tends to increase with the increase in swimbladder length. When the probability density function of the pitch angle is N(−5°, 15°), the b20 measured by the KRM and the tethered method at 70 kHz are −71.94 dB and −69.21 dB, respectively, while at 200 kHz they are −72.58 dB and −70.55 dB. This study provides a scientific basis for future acoustic target discrimination and stock assessment of C. lucidus in the Yangtze River Estuary.

Digital remote assessment of speech acoustics in cognitively unimpaired adults: feasibility, reliability and associations with amyloid pathology

BackgroundDigital speech assessment has potential relevance in the earliest, preclinical stages of Alzheimer’s disease (AD). We evaluated the feasibility, test-retest reliability, and association with AD-related amyloid-beta (Aβ) pathology of speech acoustics measured over multiple assessments in a remote setting.MethodsFifty cognitively unimpaired adults (Age 68 ± 6.2 years, 58% female, 46% Aβ-positive) completed remote, tablet-based speech assessments (i.e., picture description, journal-prompt storytelling, verbal fluency tasks) for five days. The testing paradigm was repeated after 2–3 weeks. Acoustic speech features were automatically extracted from the voice recordings, and mean scores were calculated over the 5-day period. We assessed feasibility by adherence rates and usability ratings on the System Usability Scale (SUS) questionnaire. Test-retest reliability was examined with intraclass correlation coefficients (ICCs). We investigated the associations between acoustic features and Aβ-pathology, using linear regression models, adjusted for age, sex and education.ResultsThe speech assessment was feasible, indicated by 91.6% adherence and usability scores of 86.0 ± 9.9. High reliability (ICC ≥ 0.75) was found across averaged speech samples. Aβ-positive individuals displayed a higher pause-to-word ratio in picture description (B = -0.05, p = 0.040) and journal-prompt storytelling (B = -0.07, p = 0.032) than Aβ-negative individuals, although this effect lost significance after correction for multiple testing.ConclusionOur findings support the feasibility and reliability of multi-day remote assessment of speech acoustics in cognitively unimpaired individuals with and without Aβ-pathology, which lays the foundation for the use of speech biomarkers in the context of early AD.

Current Practices in the Assessment of Voice: A Comparison of Providers Across Different Clinical Settings

ObjectiveTo investigate the current assessment practices of speech-language pathologists (SLPs) in the United States working with adult clients with voice disorders with regard to the frequency, utility, and confidence in the use of the five elements of a comprehensive voice evaluation, as well as training, access to instrumentation, and the use of published scales. MethodsAn online survey was distributed to SLPs who currently see adults with dysphonia as part of their caseload. Clinicians in a voice-focused setting were compared to those who worked in a general medical setting. ResultsNearly all of the 86 participants reported using published validated scales for patient self-assessment and auditory-perceptual ratings. Most respondents had received training in auditory-perceptual voice assessment, acoustic assessment, and videostroboscopy, but a minority reported training in aerodynamic assessment. The majority of SLPs had access to acoustic equipment but a minority had access to the instrumentation for videostroboscopic or aerodynamic assessment. Auditory-perceptual voice evaluation was the procedure most commonly performed and most highly rated for diagnostic utility. Post-graduate training and access to instrumentation were associated with significantly higher frequency of use and confidence with all three instrumental assessment methods. SLPs in voice-focused settings were more likely to have received training in videostroboscopy and perform or interpret it. SLPs in voice-focused settings were also significantly more likely to have access to equipment for all three instrumental techniques and reported significantly higher confidence in their use. Both groups rated the utility of the different components of a voice evaluation similarly and there were no significant differences between the groups in the use of validated patient questionnaires or auditory-perceptual scales. ConclusionsMost clinicians in our survey reported following practice guidelines when performing comprehensive voice evaluations across settings despite barriers of training and access to instrumentation.

Comparison of Acoustic Parameters of Voice and Speech According to Vowel Type and Suicidal Risk in Adolescents

Globally, suicide prevention and understanding suicidal behavior represent significant health challenges. The predictive potential of voice, speech, and language appears as a promising solution to the difficulty in assessment. ObjectiveTo analyze variations in acoustic parameters in voice and speech based on vowel types according to different levels of suicidal risk among adolescents in a text reading task. MethodologyCross-sectional analytical design using non-probabilistic sampling. Our sample comprised 98 adolescents aged 14 to 19, undergoing voice acoustic assessment, along with suicidal ideation determination through the Okasha Suicidality Scale and Beck Depression Inventory. Acoustic analysis of recordings was conducted using Praat for phonetic research, Python program, Focusrite interface, and microphone to register voice and speech acoustic parameters such as Fundamental Frequency, Jitter, and Formants. Subsequently, data from adolescents with and without suicidal risk were compared. ResultsSignificant differences were observed between suicidal and non-suicidal adolescents in several acoustic aspects, especially in females in fundamental frequency (F0), signal-to-noise ratio (HNRdB) and temporal variability measured by jitter and standard deviation. In mens, differences were found in F0 and HNRdB (p < 0.05). ConclusionThis study demonstrated statistically significant variations in various voice acoustic parameters among adolescents with and without suicidal risk. These findings underscore the potential relevance of voice and speech as markers for suicidal risk.

Challenges in acoustical modeling of data centers

Data centers are physical infrastructures that house computing machines and related hardware equipment for data storage and processing. Due to the ever-increasing trend of cloud computing and the need for secure data storage, several organizations are involved in the development of large data center facilities. This new industry sector is seeing massive growth in recent years and municipalities and counties across the nation are welcoming the construction of data centers in their areas. Acoustical modeling for a data center can be challenging due to various factors and this article discusses a few such challenges that were experienced during the acoustical assessments of data center operations.

Applying the Association of Australasian Acoustical Consultants (AAAC) guideline for acoustic assessment of gymnasiums and exercise facilities to field measured heavy hard impact data.

In this paper we apply the newly published Association of Australasian Acoustical Consultants (AAAC) Guideline for Acoustic Assessment of Gymnasiums and Exercise Facilities to field measured heavy hard impact data. ISO and ASTM have working groups developing standards with regards to heavy, hard impact noise. There is an industry need for a single number rating or other evaluation system "to assess the noise and vibration impact resulting from the use and operation of both existing and proposed gymnasiums and exercise facilities consistently, accurately and fairly." Lmax sound pressure levels resulting from 22.7 kg weight drops from 150 mm height were collected in a concrete building on numerous gym flooring build ups in two different adjacencies. AAAC guidelines are applied, and single number ratings reported. The AAAC metric is compared to other existing guidelines and metrics. This brings to light the need for a comprehensive ASTM guideline for assessing structure borne noise associated with fitness areas in mixed use buildings.

Airborne acoustic assessment of impact-resistant fitness flooring systems

Fitness facilities in residential and mixed-used commercial buildings introduce important acoustic design challenges that must be considered in a building. Cardio activities such as running on treadmills, group classes for high intensity training, and weight training areas introduce high levels of unwanted noise and vibration into a building structure. Isolated floor constructions are generally coordinated and implemented during design but are not practical when buildings are completed and occupied. Impact-resistant fitness flooring systems are typically explored and installed as an alternate approach to reduce the transmission of impact noise and vibration. Non-standardized field airborne noise measurements of weight drops were conducted on an existing gym and on four possible impact-resistant fitness flooring upgrades to assess the reduction of impact noise levels in the offices located below the gym. The measurements were also compared to the HVAC background noise levels to observe the increase above background conditions and provide a subjective evaluation. The results of the measurements show that impact-resistant fitness flooring systems provide a noticeable reduction of impact noise, compared to standard fitness flooring systems. The results also show that impact-resistant fitness flooring systems that include specialty engineered shock pads as a base layer provide a significant reduction of impact noise levels.