In their Comment, the authors conclude that acoustic glint is not present in the reflection coefficient of a two-layer sediment in which the top layer is an Airy medium. They conclude, not that the original, inverse-square analysis of the glint is incorrect, but rather that the presence of glint is very sensitive to the detailed shape of the sound speed profile in the top layer.
{"title":"Response to \"Comment on 'Anomalous reflection from a two-layered marine sediment' \" [J. Acoust. Soc. Am. 156, 1524-1527 (2024)].","authors":"Michael J Buckingham","doi":"10.1121/10.0028367","DOIUrl":"https://doi.org/10.1121/10.0028367","url":null,"abstract":"<p><p>In their Comment, the authors conclude that acoustic glint is not present in the reflection coefficient of a two-layer sediment in which the top layer is an Airy medium. They conclude, not that the original, inverse-square analysis of the glint is incorrect, but rather that the presence of glint is very sensitive to the detailed shape of the sound speed profile in the top layer.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Listeners are sensitive to interaural time differences carried in the envelope of high-frequency sounds (ITDENV), but the salience of this cue depends on certain properties of the envelope and, in particular, on the presence/depth of amplitude modulation (AM) in the envelope. This study tested the hypothesis that individuals with sensorineural hearing loss, who show enhanced sensitivity to AM under certain conditions, would also show superior ITDENV sensitivity under those conditions. The second hypothesis was that variations in ITDENV sensitivity across individuals can be related to variations in sensitivity to AM. To enable a direct comparison, a standard adaptive AM detection task was used along with a modified version of it designed to measure ITDENV sensitivity. The stimulus was a 4-kHz tone modulated at rates of 32, 64, or 128 Hz and presented at a 30 dB sensation level. Both tasks were attempted by 16 listeners with normal hearing and 16 listeners with hearing loss. Consistent with the hypotheses, AM and ITDENV thresholds were correlated and tended to be better in listeners with hearing loss. A control experiment emphasized that absolute level may be a consideration when interpreting the group effects.
听者对高频声音包络中的耳际时差(ITDENV)很敏感,但这一线索的显著性取决于包络的某些特性,特别是包络中振幅调制(AM)的存在/深度。本研究测试了这样一个假设:感音神经性听力损失患者在某些条件下对 AM 的敏感性会增强,在这些条件下也会表现出更高的 ITDENV 敏感性。第二个假设是,不同个体的 ITDENV 灵敏度差异可能与 AM 灵敏度差异有关。为了能够进行直接比较,我们使用了一个标准的自适应调幅检测任务和一个旨在测量 ITDENV 灵敏度的改进版本。刺激物是以 32、64 或 128 Hz 速率调制的 4 kHz 音调,以 30 dB 的感觉水平呈现。16 名听力正常的听者和 16 名听力受损的听者尝试了这两项任务。与假设相符的是,AM 和 ITDENV 的阈值是相关的,听力损失的听者的阈值往往更高。对照实验强调,在解释群体效应时,绝对水平可能是一个考虑因素。
{"title":"Relating monaural and binaural measures of modulation sensitivity in listeners with and without hearing loss.","authors":"Virginia Best, Christopher Conroy","doi":"10.1121/10.0028517","DOIUrl":"https://doi.org/10.1121/10.0028517","url":null,"abstract":"<p><p>Listeners are sensitive to interaural time differences carried in the envelope of high-frequency sounds (ITDENV), but the salience of this cue depends on certain properties of the envelope and, in particular, on the presence/depth of amplitude modulation (AM) in the envelope. This study tested the hypothesis that individuals with sensorineural hearing loss, who show enhanced sensitivity to AM under certain conditions, would also show superior ITDENV sensitivity under those conditions. The second hypothesis was that variations in ITDENV sensitivity across individuals can be related to variations in sensitivity to AM. To enable a direct comparison, a standard adaptive AM detection task was used along with a modified version of it designed to measure ITDENV sensitivity. The stimulus was a 4-kHz tone modulated at rates of 32, 64, or 128 Hz and presented at a 30 dB sensation level. Both tasks were attempted by 16 listeners with normal hearing and 16 listeners with hearing loss. Consistent with the hypotheses, AM and ITDENV thresholds were correlated and tended to be better in listeners with hearing loss. A control experiment emphasized that absolute level may be a consideration when interpreting the group effects.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mitchell J Swann, Zachary W Yoas, Adam S Nickels, Michael H Krane, Jeff R Harris
This paper presents the use of principal component analysis (PCA) for time domain microphone array denoising to characterize an impulsive aeroacoustic source, which is illustrated with the aeroacoustic emission caused by a vortex ring/edge interaction. Prior studies have used signal processing approaches that required assumptions about the source directivity or user intervention at low signal-to-noise ratio (SNR) conditions. In this context, PCA, a matrix decomposition tool which identifies the most common features across an ensemble of observations, provides a data-driven (hands-off) approach to signal processing. For microphone array time series, particular attention is paid to the temporal alignment of the signals to facilitate PCA. A time domain approach is necessary when sources are impulsive and nonstationary. Two such signal arrangements are discussed in this work. Results from this method are in good agreement with theory, validated by prior results using an ensemble averaging approach requiring user support. Furthermore, the results of this method are improved when compared to the ensemble averaging approach without user intervention. A SNR limit is identified where PCA becomes less effective for the vortex/edge interaction problem. This SNR limit is intended to aid in the design of similar future experiments.
{"title":"Time domain characterization of nonstationary low-Mach number aeroacoustic sources using principal component analysis.","authors":"Mitchell J Swann, Zachary W Yoas, Adam S Nickels, Michael H Krane, Jeff R Harris","doi":"10.1121/10.0028377","DOIUrl":"https://doi.org/10.1121/10.0028377","url":null,"abstract":"<p><p>This paper presents the use of principal component analysis (PCA) for time domain microphone array denoising to characterize an impulsive aeroacoustic source, which is illustrated with the aeroacoustic emission caused by a vortex ring/edge interaction. Prior studies have used signal processing approaches that required assumptions about the source directivity or user intervention at low signal-to-noise ratio (SNR) conditions. In this context, PCA, a matrix decomposition tool which identifies the most common features across an ensemble of observations, provides a data-driven (hands-off) approach to signal processing. For microphone array time series, particular attention is paid to the temporal alignment of the signals to facilitate PCA. A time domain approach is necessary when sources are impulsive and nonstationary. Two such signal arrangements are discussed in this work. Results from this method are in good agreement with theory, validated by prior results using an ensemble averaging approach requiring user support. Furthermore, the results of this method are improved when compared to the ensemble averaging approach without user intervention. A SNR limit is identified where PCA becomes less effective for the vortex/edge interaction problem. This SNR limit is intended to aid in the design of similar future experiments.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aleksei I Gudimenko, Alyona D Zakharenko, Pavel S Petrov
Buckingham [(2024). J. Acoust. Soc. Am. 155, 1285-1296] analyzed the dependence of the reflection coefficient on the grazing angle in two-layer marine sediment model. The upper layer in his model consists of a fine-grained material (mud), while seawater and the basement below the mud layer are treated as homogeneous halfspaces. Buckingham's analyses revealed several narrow spikes in this dependence that appeared only in the presence of a sound velocity gradient in the mud layer, a phenomenon he called acoustic glint. His derivation was accomplished for certain specific dependencies of the sound velocity on the depth. Surprisingly, the authors appear to reach the conclusion that for a slightly different vertical sound speed profile in the mud layer the spikes are no longer present in the dependence of the reflection coefficient on the grazing angle. More precisely, the same problem is examined in this letter for the case of an n2-linear layer (often called Airy medium). Acoustic glint effect is therefore very sensitive to the exact parametrization of the mud layer.
{"title":"Comment on: \"Anomalous reflection from a two-layered marine sediment\" [J. Acoust. Soc. Am. 155, 1285-1296 (2024)] (L).","authors":"Aleksei I Gudimenko, Alyona D Zakharenko, Pavel S Petrov","doi":"10.1121/10.0028366","DOIUrl":"https://doi.org/10.1121/10.0028366","url":null,"abstract":"<p><p>Buckingham [(2024). J. Acoust. Soc. Am. 155, 1285-1296] analyzed the dependence of the reflection coefficient on the grazing angle in two-layer marine sediment model. The upper layer in his model consists of a fine-grained material (mud), while seawater and the basement below the mud layer are treated as homogeneous halfspaces. Buckingham's analyses revealed several narrow spikes in this dependence that appeared only in the presence of a sound velocity gradient in the mud layer, a phenomenon he called acoustic glint. His derivation was accomplished for certain specific dependencies of the sound velocity on the depth. Surprisingly, the authors appear to reach the conclusion that for a slightly different vertical sound speed profile in the mud layer the spikes are no longer present in the dependence of the reflection coefficient on the grazing angle. More precisely, the same problem is examined in this letter for the case of an n2-linear layer (often called Airy medium). Acoustic glint effect is therefore very sensitive to the exact parametrization of the mud layer.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ben Lineton, Rahma Abdul Rahman Al Balushi, Sian Lloyd Jones, Timothy G Leighton, Mark D Fletcher
Audible very-high frequency sound (VHFS) and ultrasound (US) have been rated more unpleasant than lower frequency sounds when presented to listeners at similar sensation levels (SLs). In this study, 17 participants rated the sensory unpleasantness of 14-, 16-, and 18-kHz tones and a 1-kHz reference tone. Tones were presented at equal subjective loudness levels for each individual, corresponding to levels of 10, 20, and 30 dB SL measured at 1 kHz. Participants were categorized as either "symptomatic" or "asymptomatic" based on self-reported previous symptoms that they attributed to exposure to VHFS/US. In both groups, subjective loudness increased more rapidly with sound pressure level for VHFS/US than for the 1-kHz reference tone, which is consistent with a reduced dynamic range at the higher frequencies. For loudness-matched tones, participants rated VHFS/US as more unpleasant than that for the 1-kHz reference. These results suggest that increased sensory unpleasantness and reduced dynamic range at high frequencies should be considered when designing or deploying equipment which emits VHFS/US that could be audible to exposed people.
{"title":"Sensory unpleasantness of very-high frequency sound and audible ultrasound.","authors":"Ben Lineton, Rahma Abdul Rahman Al Balushi, Sian Lloyd Jones, Timothy G Leighton, Mark D Fletcher","doi":"10.1121/10.0028380","DOIUrl":"https://doi.org/10.1121/10.0028380","url":null,"abstract":"<p><p>Audible very-high frequency sound (VHFS) and ultrasound (US) have been rated more unpleasant than lower frequency sounds when presented to listeners at similar sensation levels (SLs). In this study, 17 participants rated the sensory unpleasantness of 14-, 16-, and 18-kHz tones and a 1-kHz reference tone. Tones were presented at equal subjective loudness levels for each individual, corresponding to levels of 10, 20, and 30 dB SL measured at 1 kHz. Participants were categorized as either \"symptomatic\" or \"asymptomatic\" based on self-reported previous symptoms that they attributed to exposure to VHFS/US. In both groups, subjective loudness increased more rapidly with sound pressure level for VHFS/US than for the 1-kHz reference tone, which is consistent with a reduced dynamic range at the higher frequencies. For loudness-matched tones, participants rated VHFS/US as more unpleasant than that for the 1-kHz reference. These results suggest that increased sensory unpleasantness and reduced dynamic range at high frequencies should be considered when designing or deploying equipment which emits VHFS/US that could be audible to exposed people.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Relative humidity, temperature, and wind along flight paths from a 10-year simulation are used to investigate the effects of the atmospheric conditions on sonic boom loudness generated by the pseudo-Concorde and a low-boom supersonic aircraft using an acoustic wave propagation tool. Global meteorological conditions are simulated using the chemistry-climate model EMAC with ECMWF reanalysis data. The results show that atmospheric conditions lead to a seasonal variation of the perceived level for a N-wave over 10 years of flights, whereas it is difficult to identify the seasonal variation for the low-boom aircraft because the distribution of perceived levels is widely spread. The dominant effect from atmospheric conditions during acoustic propagation is found for the low-boom aircraft cruising at an altitude of 14.478 km. The molecular relaxation effect is dominant for an overpressure reduction at 10 km but does not impact the pressure waveform below 8 km. At altitudes below 8 km, the thermoviscous absorption exclusively influences the variations in pressure rise time. Moreover, acoustic wave propagation through the turbulent field was simulated at a single location. Even though the acoustic wave passed through the same turbulent field in the summer and winter cases, the loudness on the ground differs between them.
{"title":"Impact of atmospheric variations on sonic boom loudness over 10 years of simulated flights.","authors":"Rei Iura, Takahiro Ukai, Hiroshi Yamashita, Bastian Kern, Takashi Misaka, Shigeru Obayashi","doi":"10.1121/10.0028375","DOIUrl":"https://doi.org/10.1121/10.0028375","url":null,"abstract":"<p><p>Relative humidity, temperature, and wind along flight paths from a 10-year simulation are used to investigate the effects of the atmospheric conditions on sonic boom loudness generated by the pseudo-Concorde and a low-boom supersonic aircraft using an acoustic wave propagation tool. Global meteorological conditions are simulated using the chemistry-climate model EMAC with ECMWF reanalysis data. The results show that atmospheric conditions lead to a seasonal variation of the perceived level for a N-wave over 10 years of flights, whereas it is difficult to identify the seasonal variation for the low-boom aircraft because the distribution of perceived levels is widely spread. The dominant effect from atmospheric conditions during acoustic propagation is found for the low-boom aircraft cruising at an altitude of 14.478 km. The molecular relaxation effect is dominant for an overpressure reduction at 10 km but does not impact the pressure waveform below 8 km. At altitudes below 8 km, the thermoviscous absorption exclusively influences the variations in pressure rise time. Moreover, acoustic wave propagation through the turbulent field was simulated at a single location. Even though the acoustic wave passed through the same turbulent field in the summer and winter cases, the loudness on the ground differs between them.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concern over the impact of multibeam echosounders (MBES) on marine life has increased in recent years. A thorough impact assessment of acoustic sources requires both accurate modeling of the source and radiated sound field, and a biological assessment. The Joint Industry Program Acoustic Modelling Workshop in 2022 provided a set of verification scenarios for a deep-water MBES to compare modelling approaches and assess agreement across models. This work presents several relevant models designed to compute both the MBES beam patterns and propagated acoustic field. Key acoustic metrics used in impact assessment were calculated and compared using these models. The work confirmed that geometrical acoustics is well suited to the unique radiation patterns of MBES. Ray-tracing programs are relevant as well at short ranges and at long horizontal distances in the presence of large sound speed gradients. The estimation of cumulative sound exposure along a survey track is most often dominated by exposure to the main transmit beam of each sector. Accurate modelling of the near field was demonstrated to have a direct impact on final acoustic metrics and threshold ranges for various marine mammal hearing groups.
{"title":"Modelling approaches to multibeam echosounders for sound field characterizationa).","authors":"Michael Smith","doi":"10.1121/10.0028338","DOIUrl":"https://doi.org/10.1121/10.0028338","url":null,"abstract":"<p><p>Concern over the impact of multibeam echosounders (MBES) on marine life has increased in recent years. A thorough impact assessment of acoustic sources requires both accurate modeling of the source and radiated sound field, and a biological assessment. The Joint Industry Program Acoustic Modelling Workshop in 2022 provided a set of verification scenarios for a deep-water MBES to compare modelling approaches and assess agreement across models. This work presents several relevant models designed to compute both the MBES beam patterns and propagated acoustic field. Key acoustic metrics used in impact assessment were calculated and compared using these models. The work confirmed that geometrical acoustics is well suited to the unique radiation patterns of MBES. Ray-tracing programs are relevant as well at short ranges and at long horizontal distances in the presence of large sound speed gradients. The estimation of cumulative sound exposure along a survey track is most often dominated by exposure to the main transmit beam of each sector. Accurate modelling of the near field was demonstrated to have a direct impact on final acoustic metrics and threshold ranges for various marine mammal hearing groups.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the deep ocean environment with a surface duct, sound propagating within the duct leaks into the geometric shadow zone below it. However, the propagation paths and time of these leaky parts have not been fully characterized. This paper investigates the mechanism of surface duct leaky (SDL) signals based on normal mode theory. It reveals that SDL signals are caused by specific modes with grazing angles close to zero at the bottom of the surface duct. Combining the theory of diffracted sound rays, the study proposes a Segmented Propagation model (SPM) for SDL signals. The propagation paths of SDL signals are divided into three segments: S1, which extends from the source to the surface duct; S2, the segment propagating within the surface duct; and S3, the segment leading from the surface duct to the receiver. The proposed SPM describes the propagation mechanism of SDL signals and allows for precise calculation of their propagation time. Experimental data from the western Pacific are used to verify the SPM.
{"title":"Segmented propagation model for the paths and travel times of surface duct leaky signals.","authors":"Guangyu Gong, Rui Duan, Kunde Yang","doi":"10.1121/10.0028378","DOIUrl":"https://doi.org/10.1121/10.0028378","url":null,"abstract":"<p><p>In the deep ocean environment with a surface duct, sound propagating within the duct leaks into the geometric shadow zone below it. However, the propagation paths and time of these leaky parts have not been fully characterized. This paper investigates the mechanism of surface duct leaky (SDL) signals based on normal mode theory. It reveals that SDL signals are caused by specific modes with grazing angles close to zero at the bottom of the surface duct. Combining the theory of diffracted sound rays, the study proposes a Segmented Propagation model (SPM) for SDL signals. The propagation paths of SDL signals are divided into three segments: S1, which extends from the source to the surface duct; S2, the segment propagating within the surface duct; and S3, the segment leading from the surface duct to the receiver. The proposed SPM describes the propagation mechanism of SDL signals and allows for precise calculation of their propagation time. Experimental data from the western Pacific are used to verify the SPM.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael A Ainslie, Robert M Laws, Michael J Smith, Alexander O MacGillivray
Evaluation of possible effects of underwater sound on aquatic life requires quantification of the sound field. A marine sound source and propagation modelling workshop took place in June 2022, whose objectives were to facilitate the evaluation of source and propagation models and to identify relevant metrics for environmental impact assessment. The scope of the workshop included model verification (model-model comparison) and model validation (model-measurement comparison) for multiple sources, including airguns, a low-frequency multi-beam echo sounder, and a surface vessel. Several verification scenarios were specified for the workshop; these are described herein.
{"title":"Source and propagation modelling scenarios for environmental impact assessment: Model verificationa).","authors":"Michael A Ainslie, Robert M Laws, Michael J Smith, Alexander O MacGillivray","doi":"10.1121/10.0028135","DOIUrl":"https://doi.org/10.1121/10.0028135","url":null,"abstract":"<p><p>Evaluation of possible effects of underwater sound on aquatic life requires quantification of the sound field. A marine sound source and propagation modelling workshop took place in June 2022, whose objectives were to facilitate the evaluation of source and propagation models and to identify relevant metrics for environmental impact assessment. The scope of the workshop included model verification (model-model comparison) and model validation (model-measurement comparison) for multiple sources, including airguns, a low-frequency multi-beam echo sounder, and a surface vessel. Several verification scenarios were specified for the workshop; these are described herein.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142120134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S K Takazawa, S K Popenhagen, L A Ocampo Giraldo, E S Cardenas, J D Hix, S J Thompson, D L Chichester, M A Garcés
For prompt detection of large (>1 kt) above-ground explosions, infrasound microphone networks and arrays are deployed at surveyed locations across the world. Denser regional and local networks are deployed for smaller explosions, however, they are limited in number and are often deployed temporarily for experiments. With the expanded interest in smaller yield explosions targeted at vulnerable areas such as population centers and key infrastructures, the need for more dense microphone networks has increased. An "attritable" (affordable, reusable, and replaceable) and flexible alternative can be provided by smartphone networks. Explosion signals from a fuel air explosive (thermobaric bomb) and a high explosive with trinitrotoluene equivalent yields of 6.35 and 3.63 kg, respectively, were captured on both an infrasound microphone and a network of smartphones. The resulting waveforms were compared in time, frequency, and time-frequency domains. The acoustic waveforms collected on smartphones produced a filtered explosion pulse due to the smartphone's diminishing frequency response at infrasound frequencies (<20 Hz) and was found difficult to be used with explosion characterization methods utilizing waveform features (peak overpressure, impulse, etc.). However, the similarities in time frequency representations and additional sensor inputs are promising for other explosion signal identification and analysis. As an example, a method utilizing the relative acoustic amplitudes for source localization using the smartphone sensor network is presented.
{"title":"A comparison of smartphone and infrasound microphone data from a fuel air explosive and a high explosive.","authors":"S K Takazawa, S K Popenhagen, L A Ocampo Giraldo, E S Cardenas, J D Hix, S J Thompson, D L Chichester, M A Garcés","doi":"10.1121/10.0028379","DOIUrl":"https://doi.org/10.1121/10.0028379","url":null,"abstract":"<p><p>For prompt detection of large (>1 kt) above-ground explosions, infrasound microphone networks and arrays are deployed at surveyed locations across the world. Denser regional and local networks are deployed for smaller explosions, however, they are limited in number and are often deployed temporarily for experiments. With the expanded interest in smaller yield explosions targeted at vulnerable areas such as population centers and key infrastructures, the need for more dense microphone networks has increased. An \"attritable\" (affordable, reusable, and replaceable) and flexible alternative can be provided by smartphone networks. Explosion signals from a fuel air explosive (thermobaric bomb) and a high explosive with trinitrotoluene equivalent yields of 6.35 and 3.63 kg, respectively, were captured on both an infrasound microphone and a network of smartphones. The resulting waveforms were compared in time, frequency, and time-frequency domains. The acoustic waveforms collected on smartphones produced a filtered explosion pulse due to the smartphone's diminishing frequency response at infrasound frequencies (<20 Hz) and was found difficult to be used with explosion characterization methods utilizing waveform features (peak overpressure, impulse, etc.). However, the similarities in time frequency representations and additional sensor inputs are promising for other explosion signal identification and analysis. As an example, a method utilizing the relative acoustic amplitudes for source localization using the smartphone sensor network is presented.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}