Floor Impact Noise Research Articles

Comparing self-generated noise reduction efforts and tolerance of neighbours’ noise in multi-residential buildings

Interfloor noise is a significant issue in multi-unit residential buildings and affects the quality of life of residents. Understanding the dynamics of noise generation and perception among residents is crucial for developing effective noise-management strategies. This study aims to investigate the similarities and differences in attitudes towards noise disturbance from the perspectives of both noise creators and listeners in multi-unit residential buildings. Additionally, it sought to understand the relationship between residents' efforts to minimise noise in their homes and their tolerance levels to noise from adjacent apartments. An online questionnaire survey on interfloor noise was conducted among 1989 South Koreans aged 20–89 years. The survey assessed noise reduction efforts, noise tolerance levels, and attitudes towards different types of noise during the day and night. Most respondents reported above-average noise reduction efforts, whereas noise tolerance was evenly distributed. A weak negative correlation was found between the overall effort and tolerance. However, the nighttime noise reduction effort was positively correlated with daytime noise tolerance. Despite being a primary complaint source, floor impact noise was considered less significant in residents' reduction efforts. Age-related differences were observed, with older adults showing increased effort and uniform tolerance, and younger adults focusing more on daytime noise reduction. This study underscores the need for a multifaceted approach to noise management in multi-unit residential buildings. These findings suggest that uniform strategies may be inadequate owing to the interplay between age, noise generation, and tolerance. Effective noise control may require resident education on floor impact noise, age-specific noise policies, and targeted noise reduction solutions based on the noise type and source. This approach can contribute to creating a more harmonious living environment for residents of all ages.

Reduction in Floor Impact Noise Using Resilient Pads Composed of Machining Scraps.

Floor impact noise is a significant social concern to secure a quiescent living space for multi-story building residents in South Korea. The floating floor, consisting of a concrete structure on resilient pads, is a specifically designed system to minimize noise transmission. This floating structure employs polymeric pads as the resilient materials. In this study, we investigated the utilization of helically shaped machining scraps as a resilient material for an alternative approach to floor noise reduction. The dynamic elastic modulus and loss factor of the scrap pads were measured using the vibration test method. The scrap pads exhibited a low dynamic elastic modulus and a high loss factor compared to the polymeric pads. Heavyweight impact sound experiments in an actual building were conducted to evaluate the noise reduction performance. The proposed pads showed excellent performance on the reduction in the structure-borne vibration of the concrete slab and resulting sound generation. The analytical model was used to simulate the response of the floating floor structure, enabling a parametric study to examine the effects of the resilient layer viscoelastic properties. Both experimental and analytical evidence confirmed that the proposed scrap pads contribute to the development of sustainable solutions for the minimization of floor impact noise.

Comparative analysis of the heavy-weight floor impact noises using different types of EVA resilient materials

The present study aims to improve the floor impact noises using various shapes of EVA resilient materials in composite floor structures. In order to this, three different types of EVA resilient materials were used including flat plate, deck plate type and cavity type of EVA boards. All the composite structure consisted of PP panel, PET and EVA resilient materials with a total depth from 30mm to 40mm. Total of 9 specimens were made for floor impact sound measurements. All the floor impact sound measurements were done at the recognized testing authority using bang machine. The values of L'I,Fmax,AW were deduced from every measurements. As a result, among the various types EVA resilient materials, most high performances were drawn when cavity type of EVA resilient material was used. It was shown that the average L'I,Fmax,AW value of cavity type was 46dB while 47dB for deck plate type, 48dB for flat plate were measured in average. It can be recognized that the good performance of cavity type EVA materials is caused by the both air layer gap beneath EVA board and air cavity inside the EVA board as well as the low dynamic elastic modulus of EVA.

Review of floor impact sound insulation performance measurement evaluation methods and timber floor specifications in Japan

Since the 1970s, heavy-weight floor impact noise has been a concern in Japan, prompting the development of unique measurement and evaluation methods standardized by JIS (Japanese Industrial Standards). JIS A 1418-1 specifies the measurement method for light-weight floor impact sound insulation performance, while JIS A 1418-2 defines the measurement method for heavy-weight floor impact sound insulation performance. Two types of standard impact sources, namely car-tire impact source and rubber ball impact source, are specified for measuring the heavy-weight floor impact sound insulation performance. JIS A 1419-2 defines the evaluation method for floor impact sound insulation performance. These methods differ from the international ISO standards, making performance comparison challenging. This paper provides an overview of these Japanese methods. Furthermore, since the enforcement of "the Act on Promotion of Use of Wood in Buildings to Contribute to the Realization of a Decarbonized Society," construction of timber buildings has been promoted in Japan with the aim of encouraging wood usage and contributing to the SDGs (Sustainable Development Goals). However, the floor impact sound insulation performance of timber floors tends to be low, with various specifications for timber floor cross-sections differing among private companies. This paper introduces these specifications and also compares driving-point impedances.

Floor impact sound insulation performance of Korean domestic cross-laminated timber floors and the influence of resilient materials' dynamic stiffness

In this study, the floor impact sound insulation performance of floors made of korean domestic cross-laminated timber panels and with a resilient layer under concrete topping was evaluated. The properties of resilient materials used in the floors were measured to evaluate their influence on floor impact sound insulation performance. The results indicate that the highest reduction levels were provided by glass fiber, expanded polystyrene and wood fiber, in diminishing order, for both heavy-weight and light-weight floor impact sounds. Through the evaluation of dynamic stiffness and single-number quantities, a high correlation was observed at 125 Hz and 500 Hz for heavy-weight floor impact sounds and across all octave bands for light-weight floor impact sounds. The analysis of dynamic stiffness and single number quantity revealed a high correlation in both heavy weight and light weight floor impact sound. Lower dynamic stiffness was confirmed to be advantageous for reducing floor impact noise.

The Improvement in the Floor Impact Noise with Changes in the Glass Transition Temperature of an SBR Latex Mortar

The Improvement in the Floor Impact Noise with Changes in the Glass Transition Temperature of an SBR Latex Mortar

The relationship between noise sensitivity and the perception of floor impact noise

Noise sensitivity is a factor that determines how an individual perceives how uncomfortable a sound is, and noise sensitivity is believed to affect the annoyance response to floor impact noise in dwellings. In this study, we conducted a survey using the Weinstein Noise Sensitivity Scale given to subjects who participated in an evaluation of annoyance to floor impact noise and investigated the relationship with the results of the annoyance judgments. As with previous research, it is predicted that the reaction to annoyance to floor impact sound varies greatly depending on the listener’s noise sensitivity and that a reaction of “annoy” is more likely to occur in the high sensitivity group, while a “annoy” judgment is less likely to occur in the low sensitivity group.

Relationship between non-destructive inspection and heavy-weight floor impact noises in a box-type test building

This study investigated the relationship between floor impact noise performance and non-destructive inspection methods for use in construction quality control prior to installing resilient floor-topping materials. The study measured floor impact noise characteristics using heavy-weight impact sources in a box-type test building with a 180-mm thick bare slab. The study employed impact echo and ultrasonic tomography methods to estimate concrete thickness and other mechanical properties. The results showed that the highest impact noise levels were observed at the central area in the frequency bands of 25 Hz to 50 Hz. However, the frequency bands of 63 Hz to 80 Hz showed different results as a peak characteristic at the middle area in the long direction. The study estimated the average slab thickness as 175 mm and 172 mm, respectively, using the impact echo and ultrasonic tomography methods. The standard deviation of the thickness was up to 9.3 mm and 6.6 mm, respectively, depending on the impact position. Furthermore, the study analyzed the correlation between concrete thickness and impact noise performance by frequency bands and discussed the application directions of the mechanical properties to manage noise performances during construction.

Numerical Investigation on the Natural Frequency of RC Slab Reinforced with Cambered Steel Beam for Reducing Heavy-Weight Impact Noise

In an apartment building, inter-floor noise occurs due to the residents' movements. The floor impact noises are divided into light and heavy-weight impact sounds depending on the impact source. This study proposed cambered steel beam reinforcement technology installed under floor slab to reduce heavy-weight impact noise. The beam for stiffness reinforcement is supported by both side of the walls in the ceiling structure, and it reduces inter-floor noise by applying upward force to the bottom surface of the slab and controlling the slab vibration characteristics. In order to verify the effectiveness of the proposed technology and investigate the natural frequency of the floor, finite element analysis model was developed for the 84m2 type apartment plan with bearing wall structure. From the eigenvalue analysis, it is known that the first natural frequency increased by 0.37~12.67% depending on the cross-section size of the cambered steel beam. Based on the first natural frequency, as a result of evaluating the vibration standards of residential buildings presented in DIN 4150-2, the vibration characteristics of the slab were improved by reducing the vibration value KB by up to 75.20%. Therefore, this study indicated that in an apartment building reinforced with cambered steel beams, inter-floor noise caused by heavy-weight impact sound was reduced.

A literature review of floor impact noise characteristics in wooden apartment buildings using cross-laminated timber slab

In this study, the floor impact noise characteristics of wooden apartment buildings made of cross-laminated timber (CLT) slabs were analyzed through a literature review. Data on heavy-weight impact noise performance was gathered, including information on floor components such as floor topping materials and ceiling finishes. The collected data was primarily analyzed in terms of CLT slab thickness. The results showed that 150 mm-thick bare CLT slabs had a single number rating of 70 to 77 dB when tested with a rubber ball, but this decreased to 64 dB for a 210 mm-thick bare slab. The addition of lower ceiling finishes and floor-topping materials could reduce the heavy-weight impact noise level to around 50 dB. However, results using a bang machine indicated 5 dB higher levels than those obtained with the rubber ball. The floor impact noise characteristics of CLT structures were also compared to those of concrete structures. The paper concludes by discussing directions for improving the floor impact noise isolation performance of CLT buildings.

Strengthening Slab Stiffness to Reduce Heavy-weight Impact Noise on the Floor

This study investigates the sound insulation performance of floor impact noise reduction method by slab stiffness reinforcement that can be applied to the existing lower unit of the apartment. The problem of floor impact noise is a major cause of conflict between upper and lower floor residents. Two experiments were conducted to verify the load capacity of the reinforcement system and to measure the noise and vibration reduction performance. The results showed that the slab stiffness reinforcement can generate up to 67 kN of load and can significantly reduce the sound pressure level and acceleration of floor impact noise in low frequencies, especially around 25Hz. The conclusion is that slab stiffness reinforcement is a feasible and effective method to improve the sound insulation performance of floor impact noise in apartment buildings.

Comparative Analysis of the Acoustic Performances of Modular and Ordinary Classrooms

Since 2016, modular construction system was introduced to Korean school buildings as it gave both of benefits in time and economical gain. Though the modular school buildings are temporarily employed during the period while students were rapidly increasing due to the regional developments, government has a responsibility to maintain the building performance for the education purposes. The purpose of this study is to investigate the classroom acoustic performance of modular school buildings. To this end, room acoustic parameters were measured in classrooms in four modular school buildings. In addition, acoustic parameters including standardized sound insulation levels were measured to analyze the sound insulation performance of walls and floor impact noise performance. At the same time, equivalent acoustic parameters were measured in normal school classrooms for comparative analysis. As a result, it was found that background noise levels of each classroom are satisfactory with the standard of 35 dB(A). Concerning room acoustic performance, modular classrooms were found to have better values than ordinary classrooms. Als, as for the sound insulation of walls and floor, it was found that modular classrooms have better sound insulation performance than the ordinary classrooms beyond the general expectations.

Classification of the location of floor impact noise using AI model based on temporal, spectral, and spatial features in apartment building

In Korea, conflicts are occurring due to misidentification of the floor impact noise (upper floor or other floors). In this study, the characteristics of floor impact noise that can effectively classify the location of floor impact noise were investigated using AI. Floor impact noise was recorded on the upper 3 floors and the lower 3 floors based on the excitation floor, and temporal, spectral, and spatial features were extracted for each floor location of floor impact noise. Based on the extracted features, the location of floor impact noise was classified through CNN and ANN. The performance of the models through each feature was compared and analyzed with the accuracy values shown through the same data. Finally, this study presented the most effective features and AI models for classifying the location of floor impact noise.

Performance of floor mats for heavy-weight impact noise reduction in a 210 mm-thick bare slab apartment houses

This study aims to understand the noise reduction performance of floor mats used to cover living room areas to reduce impact noise from children's jumping or walking. Several types of floor mat products, chosen based on their material and thickness, were selected from the market. The thickness of the mats ranged from 20 mm to 40 mm. The floor impact noise characteristics of a 210- mm thick bare slab in an actual apartment house were measured before and after the installation of the floor mat. The results showed that the highest noise reduction performance of up to 5 dB was observed when using a heavy-weight impact source with a bang machine. However, the highest noise reduction performance of up to 8 dB was observed when using a rubber ball as the heavy-weight impact source. The impact of a rubber ball dropped from a height of 40 cm, which simulates frequent living noise, resulted in a maximum reduction of up to 12 dB. In addition, the study discussed standardized methods for rating the heavy-weight impact noise performance of floor mats based on the measurement results.

Comparative analysis of the heavy-weight floor impact noises using various shapes of EVA resilient materials

Social issues concerning the floor impact noises are increasing as apartments are being increased in Korea. The present study aims to improve the floor impact noises using various shapes of EVA resilient materials in composite floor structures. In order to this, three different shapes of EVA resilient materials were used including flat plate type, deck plate type, and cavity type of EVA. boards. All the composite structure consisted of PP panel, PET sound absorption materials and EVA resilient materials with a total depth of 40mm. Also, each shape of EVA has two different types according to the use of foothold of EVA materials. For the mount type of structure, the used numbers of EVA foothold was 25, 56, and 41 per 1 m2 of area. All the floor impact noise measurements were done at the recognized testing authority using impact ball as the standard heavy-weight floor impact sound source. The values of L’i, Fmax, and AW were deduced from every measurements. As a result, regardless of the EVA shapes, better performances were drawn when EVA footholds were used, i. e., mount type. It was shown that the average L’i, Fmax, and AW value of mount types was 41–42dB while average value of 47–48 dB for deck plate type. 50–55 dB for flat plate and cavity type were measured. It can be recognized that the good performance of mount type EVA materials is caused by the air layer gap around the EVA footholds as well as the low dynamic elastic modulus of EVA.

Round-robin tests of the different types of sensors for floor impact sounds and vibrations

Recently, floor impact noise monitoring system was introduced for residents to control making noises spontaneously using sound and vibration sensors. The present study aims to investigate the performance and characteristics of various current using sound and vibration sensors which can be eventually compatible with the floor impact noise monitoring system. For measurements of sound sensors, 7 sound microphones were used including 2 condenser types, 4 dynamic types, and 1 electro condenser type. Also, 6 vibration meters were used including 2 MEMS types, 2 Piezo types, and 2 spring types. Sound levels were measured in a semi-anechoic chamber using white noise in the frequency range from 63 Hz to 12.5 kHz. Vibrations were measured using high density wooden panel with an impact ball in the frequency range from 16 Hz to 4 KHz. Round-robin tests were done to confirm the exact performances of all the sensors under same condition. As a result, it was found that dynamic type microphones show the most similar response characterization in comparison with the reference condenser microphone especially in the air-borne sound frequency range from 250 Hz to 2 KHz. Also, it was found that spring type vibration meters show the most appropriate characterization at 63 Hz, most critical structure-borne sound frequency. Thus, the results drawn from the round-robin tests could be used for floor impact noise monitoring systems with the benefit of both economy and performance.

Comparative examination of the relationship between personal and social factors and annoyance on floor impact noise using survey and laboratory methods

Comparative examination of the relationship between personal and social factors and annoyance on floor impact noise using survey and laboratory methods

Floor impact noise—The history and future of ASTM E3133

The fundamental purpose of ASTM E3133 is to provide a test method for rating the relative noisiness of floor impacts (e.g., footfalls, dropped objects, and rolling carts) on a variety of finished flooring products. Unlike previous impact noise standards which only address the impact noise radiated to other nearby spaces, the focus of this test method is to evaluate the noise radiating into the source room where the floor impacts occur. Health care facilities and performing arts venues are an obvious application, but data of this type may also be important in other facility types including schools, churches, and courtrooms. Major flooring product manufacturers have been asking for this type of standardized test data for many years. This presentation will highlight the work conducted over the last decade in the development of this standard, culminating in the adoption of the standard in 2018, its recent withdrawal, and plans for a future revision.

Estimation of impact sound reduction by wood flooring installation in a wooden building in Korea

Multi-family homes have been constructed traditionally using heavy materials like concrete/steel and bricks. Wooden structures are a promising substitute for typical heavyweight constructions. However, floor impact noise has been identified as the most annoying noise source in South Korea. Here, we have studied the effect of floorboard installation on impact sound changes before and after installing the floorboard on the floor of a wooden building. We used standard tapping and bang machines in this study to generate lightweight and heavyweight impact sounds. The changes in noise from lightweight and heavyweight impact sounds were estimated on the upper layer (UL) and lower layer (LL) floors before and after the installation of the plywood floorboard (PFB). The average of the octave band center frequencies at 125, 250, 500, 1000, and 2000 Hz from the lightweight impact before installation of PFB was 84.08 dB (UL) and 50.54 dB (LL), respectively, while 84.04 dB (UL) and 41.90 dB (LL) after the installation of the surface decorated PFB. Similarly, the heavyweight impact sound before installing PFB was 73.26 dB (UL) and 42.16 dB (LL), respectively, while after installation of PFB, impact sound appeared at 71.58 dB (UL) and 42.48 dB (LL). The results exhibited that lightweight impact sound could be reduced by about 8.6 dB on the LL. These results could entice the researcher or building engineer to design wooden floorboards for a comfortable building environment. This study is new because it compares the impact sound of the floor before and after it has been constructed.

Quantitative study on the influence of non-acoustic factors on annoyance due to floor impact noise in apartments

This study conducted quantitative research on the non-acoustic factors affecting annoyance due to floor impact noise in apartment buildings. Studies on non-acoustic factors affecting noise annoyance were mostly based on environmental noise and lacked research on floor impact noise. This study surveyed annoyance and non-acoustic factors of floor impact noise—the main noise that annoyed apartment residents. Consequently, non-acoustic factors affecting annoyance due to floor impact noise were classified into three groups: Group 1 (behavioural coping, awareness of the neighbours’ living patterns, conflict experience with the upper unit, noise sensitivity, fear and concern, and annoyance due to complaints) related to noise sources; Group 2 (beliefs and expectations, attitude towards the upper unit neighbours, attitude towards the neighbours (personal opinion), coping strategies, and closeness with neighbours) related to neighbours; and Group 3 (attitude towards construction companies, authorities, and policies) related to institutions. Moreover, the correlation between all non-acoustic factors and annoyance due to floor impact noise showed statistically significant results, with behavioural coping as the factor with the highest correlation. The results of the multiple regression analysis showed that the non-acoustic factors examined in this study could explain approximately 70% of annoyance due to floor impact noise. Furthermore, Group 1 (related to noise source) affected annoyance due to floor impact noise the most, with awareness of the neighbours’ living patterns causing the highest effect.