Sound Intensity Level Research Articles

Acoustic near field effects in distribution transformer noise measurement

This paper examines the near field effect, including the active and reactive acoustic field around a liquid-filled distribution transformer with heat-dissipating corrugated fins on the tank walls. The analysis was carried out on the basis of measurements of sound pressure and sound intensity levels along with acoustic maps including the phase correlation of acoustic waves. The acoustic field around the transformer was evaluated in the measurement planes showing normal direction radiation of up to 1,0 m distance. Discrete point measurements made with the PU (pressure - velocity) probe was used to obtain parameters such as particle velocity, active and reactive sound intensity as well as the transfer function associated with the reference microphone. The last parameter, the transfer function, allows to show the phase correlation between acoustic wave propagation, which contributes to a better understanding of acoustic near-field effects where energy circulates, creating a sound field that can have overestimated sound pressure and intensity levels.

Unequal segment areas and corner positions with the enveloping surface method for sound power determination

The standardised methods for the determination of the sound power level according to the enveloping surface methods require a measurement of the sound pressure or sound intensity level on the enveloping surface. While the subdivision of the enveloping surface into unequal segment areas is correctly standardised for the intensity method (ISO 9614, all parts), the sound pressure methods (e.g. ISO 3744) reveal some fuzziness. The reason is the necessary allocation of partial surfaces to measurement points which are normatively located at corners or edges of the parallelepiped measurement surfaces. This effect is especially important with the proposed local increase of the measurement point density in regions of increased sound radiation. The contribution shows which effects unequal areas have and how a correct surface averaging can be implemented in these cases.

The effect of the angular error on the determination of the sound power levels of industrial coolers

Drycoolers are relevant noise sources in many industrial plants due to their typically exposed positioning. For this reason, drycoolers are often subject to strict acoustic requirements in the form of maximum permissible sound power levels. Thus, the suppliers have to provide proof of compliance with these requirements before delivery. The acoustic verification measurement is usually carried out by measuring the sound pressure level using the enveloping surface method in accordance with EN 13487. According to EN 13487, the measurement is carried out at discrete points on a cuboid measuring surface. Since drycoolers are sound sources that extend over a large area, an angular error occurs when measuring sound pressure levels on a cuboid measuring surface, which leads to a superelevation of the measured sound pressure level, since the acoustic particle velocity on the cuboid measuring surface is not perpendicular to the measuring surface at almost any point. Therefore, the sound power level determined is methodically too high. By measuring the sound intensity levels in accordance with ISO 9614-2 instead of the sound pressure levels, the influence of this angular error can be excluded and brought into good agreement with theoretical considerations and calculations of the angular error.

Investigating the Sound Absorption Properties of Silk Cotton and Other Sound-Absorbent Materials

This research investigates the acoustic properties of various materials to mitigate sound transmission and enhance acoustic environments, focusing on silk cotton, cotton wool, chipped foam, and open-cell polyurethane foam. The study evaluates these materials for sound absorption and reduction, considering sound frequency and material density. Materials were tested for their sound reduction and absorption coefficients, with silk cotton emerging as the most effective across a broad frequency spectrum, particularly below 200 Hz and above 1000 Hz. The research demonstrated that silk cotton, with its high porosity and fine fibre structure, achieved significant sound reduction even at low densities The findings align with theoretical predictions of resonance frequencies, showing a strong correlation (r2 = 0.9988 for the sound box and r2 = 0.9894 for the sound pipe). Sound intensity and sound pressure levels were measured using a sound level meter, and data analysis was conducted using graphing and calculating software. The researcher employed modified laboratory methods to account for loose materials and equipment limitations, validating the use of theoretical equations to estimate sound absorption and reduction properties The study provides some insights into using fibrous materials like silk cotton for noise reduction and acoustic enhancement. These findings have practical implications for improving sound quality in various environments, such as schools, studios, and public spaces, contributing to noise reduction strategies and enhancing auditory experiences.

Toward Sham Interventions for Behavioral Voice Treatment Outcome Research in Female Students Without Dysphonia

Objectives/HypothesisTo develop sham voice treatment techniques to be used in voice treatment outcomes research, and to investigate their effectiveness as sham. This entails that the techniques induce no changes in voice or voice physiology, yet still lead to a perception of efficacy. Study DesignProspective randomized blinded controlled study MethodsThree distinct sham intervention protocols (SIPs) were conceptualized as placebic comparators for three common voice treatment approaches with focus on vocalization (SIP1), respiration (SIP2), and manipulation (SIP3). Forty-eight female students participated in the study. Each participant attended ten 30-minute sessions over five weeks, including a baseline evaluation, three sessions of one SIP, an inter-SIP voice assessment, three sessions of a second SIP, and a final post-SIPs assessment. Auditory-perceptual and instrumental voice evaluations were used as voice treatment outcomes measures. The participants' perception of voice-related quality of life was evaluated using the French Voice Handicap Index (VHIFR). Frequentist as well as Bayesian statistical methods were applied for group comparisons. The effects of combining two SIPs, the potential influence of SIP order, and experimenter/clinician effects were also investigated. ResultsThe respiration-based SIP2 showed changes only in sound intensity level on sustained vowel across the three sham intervention sessions. In contrast, the vocalization-based SIP1 impacted sound intensity level on sustained vowel, sound intensity level on read text, and maximum phonation time. The manipulation-based SIP3 affected smoothed cepstral peak prominence on read text, Acoustic Voice Quality Index, and Dysphonia Severity Index. SIP2 thus demonstrated the highest alignment with the study's objectives, followed by SIP1 and SIP3. GRBASI ratings revealed no statistical differences for any SIP. VHIFr decreased significantly after all three SIPs. Combining the SIPs generally replicated the effects observed when each SIP was used individually. There was no order effect or experimenter/clinician effect on the results. ConclusionsThis study demonstrated significant changes in participants' perceived voice quality (measured with VHIFr) across various sham intervention protocols, despite minimal impact on objective voice function measures. Further investigation is necessary to establish one or more protocols as genuinely sham interventions.

The Effect of Rapeseed Oil Biopolyols and Cellulose Biofillers on Selected Properties of Viscoelastic Polyurethane Foams.

This paper presents the results of research on polyurethane viscoelastic foams (PUVFs) modified with biomaterials. This investigation looked at the effect of the biomaterials on the foaming processes, as well as the acoustical and selected physical-mechanical properties of the foams. Various types of rapeseed oil biopolyols and microcellulose were used to modify the materials. The analysis of properties covered a reference biopolyol-free sample and materials containing 10 wt.%, 20 wt.%, and 30 wt.% of different types of biopolyols in the mixture of polyol components. The biopolyols differed in terms of functionality and hydroxyl value (OHv). Next, a selected formulation was modified with various microcellulose biofillers in the amount of 0.5-2 wt.%. The PUVFs, with apparent densities of more than 210 kg/m3 and open-cell structures (more than 85% of open cells), showed a slow recovery to their original shape after deformation when the pressure force was removed. They were also characterized by a tensile strength in the range of 156-264 kPa, elongation at break of 310-510%, hardness of 8.1-23.1 kPa, and a high comfort factor of 3.1-7.1. The introduction of biopolyols into the polyurethane system resulted in changes in sound intensity levels of up to 31.45%, while the addition of fillers resulted in changes in sound intensity levels of up to 13.81%.

Normoacusia y discriminación verbal en entornos sonoros reales

IntroductionHuman beings are constantly exposed to complex acoustic environments every day, which even pose challenges for individuals with normal hearing. Speech perception relies not only on fixed elements within the acoustic wave but is also influenced by various factors. These factors include speech intensity, environmental noise, the presence of other speakers, individual specific characteristics, spatial separatios of sound sources, ambient reverberation, and audiovisual cues. The objective of this study is twofold: to determine the auditory capacity of normal hearing individuals to discriminate spoken words in real-life acoustic conditions and perform a phonetic analysis of misunderstood spoken words. Materials and methodsThis is a descriptive observational cross-sectional study involving 20 normal hearing individuals. Verbal audiometry was conducted in an open-field environment, with sounds masked by simulated real-word acoustic environment at various sound intensity levels. To enhance sound emission, 2D visual images related to the sounds were displayed on a television. We analyzed the percentage of correct answers and performed a phonetic analysis of misunderstood spanish bisyllabic words in each environment. Results14 women (70%) and 6 men (30%), with an average age of 26±5,4 years and a mean airway hearing threshold in the right ear of 10,56±3,52dB SPL and in the left ear of 10,12±2,49dB SPL. The percentage of verbal discrimination in the ‘Ocean’ sound environment was 97,2±5,04%, ‘Restaurant’ was 94±4,58%, and ‘Traffic’ was 86,2±9,94% (p=0,000). Regarding the phonetic analysis, the allophones that exhibited statistically significant differences were as follows: [o] (p=0,002) within the group of vocalic phonemes, [n] (p=0,000) of voiced nasal consonants, [ɾ] (p=0,0016) of voiced fricatives, [b] (p=0,000) and [g] (p=0,045) of voiced stops. ConclusionsThe dynamic properties of the acoustic environment can impact the ability of a normal hearing individual to extract information from a voice signal. Our study demonstrates that this ability decreases when the voice signal is masked by one or more simultaneous interfering voices, as observed in a ‘Restaurant’ environment, and when it is masked by a continuous and intense noise environment such as ‘Traffic’. Regarding the phonetic analysis, when the sound environment was composed of continuous-low frequency noise, we found that nasal consonants were particularly challenging to identify. Furthermore, in situations with distracting verbal signals, vowels and vibrating consonants exhibited the worst intelligibility.

Normal hearing and verbal discrimination in real sounds environments

IntroductionHuman beings are constantly exposed to complex acoustic environments every day, which even pose challenges for individuals with normal hearing. Speech perception relies not only on fixed elements within the acoustic wave but is also influenced by various factors. These factors include speech intensity, environmental noise, the presence of other speakers, individual specific characteristics, spatial separatios of sound sources, ambient reverberation, and audiovisual cues. The objective of this study is twofold: to determine the auditory capacity of normal hearing individuals to discriminate spoken words in real-life acoustic conditions and perform a phonetic analysis of misunderstood spoken words. Materials and methodsThis is a descriptive observational cross-sectional study involving 20 normal hearing individuals. Verbal audiometry was conducted in an open-field environment, with sounds masked by simulated real-word acoustic environment at various sound intensity levels. To enhance sound emission, 2D visual images related to the sounds were displayed on a television. We analyzed the percentage of correct answers and performed a phonetic analysis of misunderstood Spanish bisyllabic words in each environment. Results14 women (70%) and 6 men (30%), with an average age of 26 ± 5,4 years and a mean airway hearing threshold in the right ear of 10,56 ± 3,52 dB SPL and in the left ear of 10,12 ± 2,49 dB SPL. The percentage of verbal discrimination in the “Ocean” sound environment was 97,2 ± 5,04%, “Restaurant” was 94 ± 4,58%, and “Traffic” was 86,2 ± 9,94% (p = 0,000). Regarding the phonetic analysis, the allophones that exhibited statistically significant differences were as follows: [o] (p = 0,002) within the group of vocalic phonemes, [n] (p = 0,000) of voiced nasal consonants, [r] (p = 0,0016) of voiced fricatives, [b] (p = 0,000) and [g] (p = 0,045) of voiced stops. ConclusionThe dynamic properties of the acoustic environment can impact the ability of a normal hearing individual to extract information from a voice signal. Our study demonstrates that this ability decreases when the voice signal is masked by one or more simultaneous interfering voices, as observed in a “Restaurant” environment, and when it is masked by a continuous and intense noise environment such as “Traffic”. Regarding the phonetic analysis, when the sound environment was composed of continuous-low frequency noise, we found that nasal consonants were particularly challenging to identify. Furthermore in situations with distracting verbal signals, vowels and vibrating consonants exhibited the worst intelligibility.

Evaluation of Brainstem Auditory-Evoked Potentials in Infants with Iron Deficiency Anemia

Purpose: To evaluate and compare the brain functions of infants with and without Iron Deficiency anaemia (IDA) electrophysiologically with brainstem auditory potentials (BAEPs). Materials and Methods: BAEP tests were performed on 26 healthy infants and 26 infants with iron deficiency anaemia, aged 6-24 months, who were followed through the Paediatric Haematology Department at SDU Faculty of Medicine. Children were classified as anaemic if their haemoglobin (Hb) level fell below -2 standard deviations for their age. All patients diagnosed with iron deficiency anaemia received 5 mg/kg/day of divalent iron glycine sulphate complex in three doses daily for a duration of 12 weeks, to be taken on an empty stomach. Both group were orally administered Chloral hydrate at a dosage of 50mg/kg prior to the BAEP test to induce sedation. The BAEP was recorded at a sound intensity level of 90 decibels, with a frequency of 10 Hertz, and with click stimuli ranging from 1000 to 2000. The BAEP test was administered to the IDA group before and after treatment, as well as to the control group, with a 3-month interval between tests. Results: 14 (53.8%) of the IDA patients were males, and 16 (61.5%) of the control group were females. Patients with IDA had an average age of 14.4±3.09 months, while the control group patients have an average age of 11.2±4.04 months. Patients with iron deficiency anaemia had lower pre-treatment levels of Hb, Hct, MCV, MCH, MCHC, transferrin saturation percentage, and ferritin compared to the control group, whereas platelet and RDW values were greater (p˂0.001). The study compared the Brainstem Auditory Evoked Potential (BAEP) values of patients with Iron Deficiency Anaemia (IDA) before treatment with those of control patients. The results indicated that the III-V interval, showing nerve conduction time, was significantly prolonged in the pre-treatment BAEPs (p˂0.05). There was no significant difference in interpeak latencies between the control group and patients with iron deficiency anaemia (IDA) following therapy (p˂0.05). Significant differences were found in the I-III, III-V, and I-V interpeak latencies of individuals with iron deficiency anaemia before and after treatment (p

Prevalence of Noise Induced Hearing Loss among the Textile Workers

Background: Noise remains a common environmental pollutant in industrial workplaces and has been a constant issue since the industrial revolution. Occupational hearing loss is the dominant cause of preventable sensorineural hearing loss in adults. The degree of NIHL is determined by intensity, duration of exposure, spectral characteristics of the noise, and individual susceptibility Methods: This cross-sectional study was carried out among theNassa Taipei Textile Mills Ltd. and Nassa Taipei Spinners Ltd in kachpur,Narayangonj.200 Textile workers aged from 18 to 50 years were recruited in this study. Study subjects were interviewed by trained data collector through a structured questionnaire. Environmental sound intensity level in various departments were measured using a sound level meter (Quest sound level meter, Oconomowoc WISCONSIN. Model no: 2400). Pure Tone Audiometry was done by pure tone clinical audiometer (KAMPLEX Audiometer, Model no: AC 30; Calibrated by P.C. Werth Limited in October 2004) with a frequency range of 125Hz to 8000Hzand sound intensity levels of between -10dB to 120dB was used to test each ear of the subject separately. Data was analyzed using Statistical Package for Social Sciences (SPSS) program version 26. Results: Out of 200 Textile workers whose were recruited in this study, 138(69%) were males and predominant age group was 18 to 27 years (54.5%). The prevalence of NIHL was found to be 14.5%. The most common age group was 28 to 37 years and positive association (p<.05) between hearing loss and long working hours. Non-user of PPD had little bit higher among the workers who developed hearing loss. Conclusion: The prevalence of NIHL was higher in textile industry workers. This suggests the need to provide protective gear to workers in stations generating loud noise. The prevalence was higher in male, those who experienced prolong exposure and not to used PPD. Bangladesh J Otorhinolaryngology 2023; 29(2): 89-95

A study of acoustic-light-thermal effects on pedestrians’ overall comfort in a Cfa-climate campus during the summer

The environmental quality, in terms of acoustic, visual, and thermal environments, significantly affects people's comfort levels. Along these lines, in this work, their comprehensive impact on people's overall comfort was systematically explored. Pedestrians' outdoor neutral points on various environmental parameters were found by performing linear regressions. Similarly, people's thermal perceptions (indicated by neutral temperatures, NT) were found to vary for both acoustic and light environments. They would be increasingly heat sensitive (R2 increases) in a noisier environment while the NTs varied for either sound or light intensity levels. From our analysis, it was demonstrated that people's overall comforts were negatively correlated with these parameters in different degrees. This work provides valuable insights for future urban design and planning studies to create better outdoor environments.

Noise Analysis Around Jababeka – Cikarang Industrial Area

Noise is an unwanted sound from a business or activity at a certain level and at a particular time that can cause disturbances to human health and environmental comfort. Noise can cause psychological and physiological impacts. The Ind is one of the largest industrial areas in Bekasi Regency, West Java. This study aims to analyse the noise levels around the industrial area of Jababeka-Cikarang. This type of research is survey research with a quantitative approach. This study measures the sound intensity level in the Jababeka–Cikarang area, up to a distance of 20 km from the Jababeka – Cikarang area. Data analysis used descriptive analysis in the form of graphs. The study results show that the noise level in the Jababeka-Cikarang area exceeds the threshold set by the Threshold, which is 70 dB to 85 dB.

Evaluation of flow, supply, and demand for noise reduction in urban area, Hamadan in Iran.

Noise pollution is one of the consequences of urbanization that can cause environmental disturbances in urban areas. Urban ecosystems provide noise reduction services through Urban Green infrastructures (UGIs). Many studies have been conducted to evaluate and model traffic noise, but none have addressed the flow, supply, and demand of noise reduction ecosystem services. The main purpose of this paper is to present a new methodology for estimating flow, supply, and demand for noise reduction in Hamadan city that has not been mentioned in any paper so far. UGIs were classified into six main categories: agricultural lands, gardens, parks, abandoned lands, single trees, and street trees. A total of 57 sampling stations for sound measurement were made in August 2018. The current map of noise pollution (flow) was created using the Kriging method. The amount of supply was measured up to a distance of 50 meters from the main roads based on two approaches (the distance effect and the sound barrier effect). To quantify the demand, the current sound intensity level in the noise-sensitive land uses was compared with standards. Zonal statistics was used for spatial analysis of supply-demand in the urban neighborhood as a working unit. Results showed that at distances of 5m, 10m, 15m, and 20m, the average noise reduction was found to be 1.61, 2.83, 3.92, and 5.33 dB, respectively. Sound barriers at distances of 5m and 10m resulted in an average sound reduction of 1.61 and 2.83 dB, respectively. Individual trees, strip trees, abandoned lands, parks, and gardens led to a decrease in traffic noise by 0.3, 1, 0.1, 3.5, and 4.5 dB, respectively. The clustering analysis revealed a significant spatial clustering of noise pollution in Hamedan. The results and new methodology of this research can be used in similar areas to estimate the supply and demand of noise reduction and also for decision-makers to take management actions to increase supply and meet the demand for noise reduction service.

Pengaruh Gaya Pukul Terhadap Intensitas Bunyi Pada Alat Musik Ketipung

This study aims to determine the effect of striking force on the sound intensity of the ketipung musical instrument made of paralon pipes with a length of 20 cm and a diameter of 114 mm on the resulting sound intensity. The research data was obtained using the experimental method. Different styles indicate different sound intensity levels, the higher the force applied, the higher the resulting sound intensity and vice versa, the lower the potential energy, the lower the sound intensity, following the equation y = 3.5341e0.7416x with y as a level function Sound intensity and x as the hitting force. Based on the results of the analysis, it can be concluded that the relationship between the hitting force per unit area and the sound intensity follows an exponential equation.

A neural network approach for prediction of tyre rolling noise during indoor tests

Nowadays, noise has become one of the main concerns of environmental pollution, especially in the automotive and transport industry. Tyre noise has a core influence and manufacturers, pushed by regulations, invest several resources in experimental tests and numerical simulations to improve their products performances. In this context, predictive models represent useful tools to support the virtual prototyping. In this paper a statistical modelling approach for the prediction of sound intensity measurements in indoor condition is proposed. Particular attention is paid to the selection of the parameters related to tyre/road noise and to their processing. At first, sound intensity levels are measured for a set of tyres rolling on drum at different speeds. Then, noise-related tyre features are measured and processed. Eventually, an artificial neural network is used to define the statical model relating these features with the measured sound intensities. Promising results support the proposed approach.

Assessment of an Open-Source Aircraft Noise Prediction Model Using Approach Phase Measurements

An open-source simulation model for aircraft noise prediction is presented and validated using backpropagated noise measurements for a state-of-the-art engine and aircraft. The validation is focused on approach procedures and was performed using ground-based noise measurements that were taken at 17 recording stations for a total of 18 consecutive flights carried out during the morning of 8 April 2021. The flights were performed using two A321neo aircraft with LEAP-1A engines. It is demonstrated that the presented noise model provides a satisfactory estimation of the source noise for varying approach configurations and flight conditions. Configurations using a greater number of high-lift devices are particularly well predicted in the mid- and high-frequency regions, whereas the lower configuration settings show greater spectral deviations, which are partly attributed to measurement uncertainties caused by the increased aircraft–microphone distance. The model can predict the overall mean total sound intensity level within a 2 dB accuracy for all configurations, while the average predicted level at each microphone differs by less than 3 dB from the measurement average, for all cases except one. Variation in aircraft speed showed to have a strong impact on the predicted total noise, which matches the well-recognized sixth-power Mach number far-field sound intensity scaling law for airframe noise models, while the measurements indicated a less significant dependency. This is mainly due to installation effects and noise reduction measures that are not included in the models. Nevertheless, the variations in the spectra of the predicted and measured noise showed similar patterns.

The role of sound stimulation in production of plant secondary metabolites

Sound vibration is one of natural stimuli trigging physiological changes in plants. Recent studies showed that sound waves stimulated production of a variety of plant secondary metabolites, including flavonoids, in order to enhance seed germination, flowering, growth or defense. In this review, we examine the potential role of sound stimulation on the biosynthesis of secondary metabolites and the followed cascade of physiological changes in plants, from the perspective of transcriptional regulation and epigenetic regulation for the first time. A systematic summary showed that a wide range of factors may regulate the production of secondary metabolites, including plant species, growth stage, sound types, sound frequency, sound intensity level and exposure time, etc. Biochemical and physiological changes due to sound stimulation were thoroughly summarized as well, for secondary metabolites can also act as a free radical scavenger, or a hormone signaling molecule. We also discussed the limits of previous studies, and the future application of sound waves in biosynthesis of plant secondary metabolites.

Physics laboratory with smartphone: sound and light

We applied smartphone technology to deliver key concepts in light and sound in the Physics Laboratory course. We used the Physics Toolbox Sensor Suite app to demonstrate the spatial and material dependence of the sound intensity level and illuminance. Self-contained modules, which consist of instruction, handouts, and analysis, are provided on the University’s Learning Management System platform to allow students to perform self-directed study on the concept through self-exploration and collaborative experimental activity. This work provides an example of an alternative but potentially powerful learning ecosystem for the future.

Pengaruh Variasi Jenis Bahan Terhadap Pengurangan Taraf Intensitas Bunyi

Acoustic materials such as plastic carpet, gypsum board, styrofoam and plywood can be used to reduce sound intensity. Nevertheless, the existing research has generally focused on single-ingredient studies. In this research, the optimum thickness of each material will be sought based on its efficiency in reducing the sound intensity level. Besides that, the efficiency of various types of materials will also be tested for reducing the level of sound intensity. In this study, a resonator tube was used in making measurements. Acoustic materials used as test materials, both single materials and combined materials, can be placed in the resonator tube. The distance between the sound source and the detector is 30 cm, with the position of the detector right behind the acoustic material. Tests on a single material show that the measured sound intensity level decreases in proportion to the thickness of the acoustic material, with styrofoam has the lowest efficiency. Meanwhile, the combined material that combines plastic carpet material at a frequency of 2000 Hz has an efficiency value that tends to be higher than the combination of materials without carpet with efficiency >30%. However, at a frequency of 1500 Hz, all combined materials have efficiency values that are not significantly different. All models of material combinations are proven to be able to reduce sound intensity levels compared to single materials. Thus, it can be concluded that the combined material has the potential as an efficient acoustic material.

ANALYSIS OF ACOUSTIC AND PHYSICAL PROPERTIES OF OIL PALM EMPTY FRUIT BUNCH PARTICLE COMPOSITE BOARDS FABRICATED WITH VARYING ADHESIVE CONTENT

A study was performed to analyze the sound intensity level and physical properties of a composite board made from oil palm empty fruit bunch (OPEFB) particles mixed with polyvinyl acetate (PVAc) adhesive. The composite boards were fabricated with various concentrations of adhesive, namely 8%, 10%, 12%, 14%, and 16%. The intensity level was measured at sound wave frequencies of 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz. The results showed that the highest sound intensity level, 74,2 dB at a frequency of 500 Hz, was found in the composite board with an 8% adhesive concentration. This composite board is categorized as a low-density composite board. The lowest sound intensity level, 58,6 dB at a frequency of 125 Hz, was found in the composite board produced with 16% adhesive concentration. This composite board is categorized as a high-density composite board. The physical property test results for all adhesive concentration variations showed that the resulting composite board density was 0,705-0,723 g/cm3, and the moisture content was 8,36%-9,66%. These values met the requirements of SNI 03-2105-2006.