Ecosystem monitoring of a seagrass meadow using wideband acoustic measurements

2021 ◽  
Vol 150 (4) ◽  
pp. A351-A351
Author(s):  
Megan S. Ballard ◽  
Kevin M. Lee ◽  
Andrew R. McNeese ◽  
Gabriel R. Venegas ◽  
Abdullah F. Rahman ◽  
...  
2018 ◽  
Vol 144 (3) ◽  
pp. 1913-1913
Author(s):  
Megan S. Ballard ◽  
Jason D. Sagers ◽  
Gabriel R. Venegas ◽  
Kevin M. Lee ◽  
Andrew R. McNeese ◽  
...  

2020 ◽  
Vol 147 (3) ◽  
pp. 2002-2019 ◽  
Author(s):  
Megan S. Ballard ◽  
Kevin M. Lee ◽  
Jason D. Sagers ◽  
Gabriel R. Venegas ◽  
Andrew R. McNeese ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 334
Author(s):  
Cecilie Sævdal Dybsland ◽  
Trine Bekkby ◽  
Kjersti Hasle Enerstvedt ◽  
Olav M. Kvalheim ◽  
Eli Rinde ◽  
...  

Chemical ecology has been suggested as a less time-consuming and more cost-efficient monitoring tool of seagrass ecosystems than traditional methods. Phenolic chemistry in Zostera marina samples was analyzed against latitude, sea depth, sample position within a seagrass meadow (periphery or center) and wave exposure. Multivariate data analysis showed that rosmarinic acid correlated moderately positively with depth, while the flavonoids had an overall strong negative correlation with increasing depth—possibly reflecting lack of stress-induced conditions with increasing depth, rather than a different response to light conditions. At a molecular level, the flavonoids were separated into two groups; one group is well described by the variables of depth and wave exposure, and the other group that was not well described by these variables—the latter may reflect biosynthetic dependencies or other unrevealed factors. A higher flavonoid/rosmarinic acid ratio was seen in the periphery of a seagrass meadow, while the contrary ratio was seen in the center. This may reflect higher plant stress in the periphery of a meadow, and the flavonoid/rosmarinic acid ratio may provide a possible molecular index of seagrass ecosystem health. Further studies are needed before the full potential of using variation in phenolic chemistry as a seagrass ecosystem monitoring tool is established.


2020 ◽  
Vol 63 (12) ◽  
pp. 3991-3999
Author(s):  
Benjamin van der Woerd ◽  
Min Wu ◽  
Vijay Parsa ◽  
Philip C. Doyle ◽  
Kevin Fung

Objectives This study aimed to evaluate the fidelity and accuracy of a smartphone microphone and recording environment on acoustic measurements of voice. Method A prospective cohort proof-of-concept study. Two sets of prerecorded samples (a) sustained vowels (/a/) and (b) Rainbow Passage sentence were played for recording via the internal iPhone microphone and the Blue Yeti USB microphone in two recording environments: a sound-treated booth and quiet office setting. Recordings were presented using a calibrated mannequin speaker with a fixed signal intensity (69 dBA), at a fixed distance (15 in.). Each set of recordings (iPhone—audio booth, Blue Yeti—audio booth, iPhone—office, and Blue Yeti—office), was time-windowed to ensure the same signal was evaluated for each condition. Acoustic measures of voice including fundamental frequency ( f o ), jitter, shimmer, harmonic-to-noise ratio (HNR), and cepstral peak prominence (CPP), were generated using a widely used analysis program (Praat Version 6.0.50). The data gathered were compared using a repeated measures analysis of variance. Two separate data sets were used. The set of vowel samples included both pathologic ( n = 10) and normal ( n = 10), male ( n = 5) and female ( n = 15) speakers. The set of sentence stimuli ranged in perceived voice quality from normal to severely disordered with an equal number of male ( n = 12) and female ( n = 12) speakers evaluated. Results The vowel analyses indicated that the jitter, shimmer, HNR, and CPP were significantly different based on microphone choice and shimmer, HNR, and CPP were significantly different based on the recording environment. Analysis of sentences revealed a statistically significant impact of recording environment and microphone type on HNR and CPP. While statistically significant, the differences across the experimental conditions for a subset of the acoustic measures (viz., jitter and CPP) have shown differences that fell within their respective normative ranges. Conclusions Both microphone and recording setting resulted in significant differences across several acoustic measurements. However, a subset of the acoustic measures that were statistically significant across the recording conditions showed small overall differences that are unlikely to have clinical significance in interpretation. For these acoustic measures, the present data suggest that, although a sound-treated setting is ideal for voice sample collection, a smartphone microphone can capture acceptable recordings for acoustic signal analysis.


2019 ◽  
pp. 40-46 ◽  
Author(s):  
V.V. Savchenko ◽  
A.V. Savchenko

We consider the task of automated quality control of sound recordings containing voice samples of individuals. It is shown that in this task the most acute is the small sample size. In order to overcome this problem, we propose the novel method of acoustic measurements based on relative stability of the pitch frequency within a voice sample of short duration. An example of its practical implementation using aninter-periodic accumulation of a speech signal is considered. An experimental study with specially developed software provides statistical estimates of the effectiveness of the proposed method in noisy environments. It is shown that this method rejects the audio recording as unsuitable for a voice biometric identification with a probability of 0,95 or more for a signal to noise ratio below 15 dB. The obtained results are intended for use in the development of new and modifying existing systems of collecting and automated quality control of biometric personal data. The article is intended for a wide range of specialists in the field of acoustic measurements and digital processing of speech signals, as well as for practitioners who organize the work of authorized organizations in preparing for registration samples of biometric personal data.


2015 ◽  
Vol 39 (2) ◽  
pp. 199-202
Author(s):  
Wojciech Batko ◽  
Renata Bal

Abstract The assessment of the uncertainty of measurement results, an essential problem in environmental acoustic investigations, is undertaken in the paper. An attention is drawn to the - usually omitted - problem of the verification of assumptions related to using the classic methods of the confidence intervals estimation, for the controlled measuring quantity. Especially the paper directs attention to the need of the verification of the assumption of the normal distribution of the measuring quantity set, being the base for the existing and binding procedures of the acoustic measurements assessment uncertainty. The essence of the undertaken problem concerns the binding legal and standard acts related to acoustic measurements and recommended in: 'Guide to the expression of uncertainty in measurement' (GUM) (OIML 1993), developed under the aegis of the International Bureau of Measures (BIPM). The model legitimacy of the hypothesis of the normal distribution of the measuring quantity set in acoustic measurements is discussed and supplemented by testing its likelihood on the environment acoustic results. The Jarque-Bery test based on skewness and flattening (curtosis) distribution measures was used for the analysis of results verifying the assumption. This test allows for the simultaneous analysis of the deviation from the normal distribution caused both by its skewness and flattening. The performed experiments concerned analyses of the distribution of sound levels: LD, LE, LN, LDWN, being the basic noise indicators in assessments of the environment acoustic hazards.


Author(s):  
J. Greenhall ◽  
C. Hakoda ◽  
E. S. Davis ◽  
V. K. Chillara ◽  
C. Pantea

2021 ◽  
pp. 136700692199680
Author(s):  
Michael Gradoville ◽  
Mark Waltermire ◽  
Avizia Long

Aims and objectives: While previous research has shown that phonetic variation in language contact situations is affected by whether a word has a cognate in the contact language, this paper aims to show that such an effect is not monotonic. According to the usage-based model, items in memory are organized according to similarity, thus we anticipated that formally more similar cognates would show a stronger cognate effect. Methodology: This variationist sociophonetic study investigates the relationship between cognate similarity and phonetic realization. We examined this relationship in the bilingual community of Rivera, Uruguay, in which both Portuguese and Spanish are spoken with regularity. Specifically, we focused on intervocalic /d/, which in monolingual Spanish is realized as an approximant [ð̞] or phonetic zero, but in monolingual Brazilian Portuguese is produced as a stop [d] or, in most varieties, an affricate [ʤ] before [i]. Data and analysis: We analyzed a corpus of sociolinguistic interviews of the Spanish spoken in Rivera. Acoustic measurements were taken from approximately 60 tokens each from 40 different speakers. Using a linear mixed-effects model, we examined the relationship between several predictors and the degree of constriction of intervocalic /d/. Findings/conclusions: While there is an overall frequency effect whereby more frequent words exhibit less constriction of intervocalic /d/, as both frequency and cognate similarity increase, less constriction of intervocalic /d/ obtains. Therefore, frequent cognates in Portuguese that have very similar forms affect the production of intervocalic /d/ more so than other cognates. Originality: No previous study has demonstrated that the cognate effect on phonetic variation in a situation of language contact is regulated by form similarity between cognate pairs. Significance/implications: The data support the usage-based model in that similar cognates have more lexical connections and can therefore show greater influence on phonetic realization than can cognates that share less phonetic material.


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