High Spectral Ratio Research Articles

Validity of Acoustic Measures Obtained Using Various Recording Methods Including Smartphones With and Without Headset Microphones.

The goal of this study was to assess various recording methods, including combinations of high- versus low-cost microphones, recording interfaces, and smartphones in terms of their ability to produce commonly used time- and spectral-based voice measurements. Twenty-four vowel samples representing a diversity of voice quality deviations and severities from a wide age range of male and female speakers were played via a head-and-thorax model and recorded using a high-cost, research standard GRAS 40AF (GRAS Sound & Vibration) microphone and amplification system. Additional recordings were made using various combinations of headset microphones (AKG C555 L [AKG Acoustics GmbH], Shure SM35-XLR [Shure Incorporated], AVID AE-36 [AVID Products, Inc.]) and audio interfaces (Focusrite Scarlett 2i2 [Focusrite Audio Engineering Ltd.] and PC, Focusrite and smartphone, smartphone via a TRRS adapter), as well as smartphones direct (Apple iPhone 13 Pro, Google Pixel 6) using their built-in microphones. The effect of background noise from four different room conditions was also evaluated. Vowel samples were analyzed for measures of fundamental frequency, perturbation, cepstral peak prominence, and spectral tilt (low vs. high spectral ratio). Results show that a wide variety of recording methods, including smartphones with and without a low-cost headset microphone, can effectively track the wide range of acoustic characteristics in a diverse set of typical and disordered voice samples. Although significant differences in acoustic measures of voice may be observed, the presence of extremely strong correlations (rs > .90) with the recording standard implies a strong linear relationship between the results of different methods that may be used to predict and adjust any observed differences in measurement results. Because handheld smartphone distance and positioning may be highly variable when used in actual clinical recording situations, smartphone + a low-cost headset microphone is recommended as an affordable recording method that controls mouth-to-microphone distance and positioning and allows both hands to be available for manipulation of the smartphone device.

Smartphone Recordings are Comparable to “Gold Standard” Recordings for Acoustic Measurements of Voice

PurposeThe purpose of this study was to assess the relationship and comparability of cepstral and spectral measures of voice obtained from a high-cost “flat” microphone and precision sound level meter (SLM) vs. high-end and entry level models of commonly and currently used smartphones (iPhone i12 and iSE; Samsung s21 and s9 smartphones). Device comparisons were also conducted in different settings (sound-treated booth vs. typical “quiet” office room) and at different mouth-to-microphone distances (15 and 30 cm). MethodsThe SLM and smartphone devices were used to record a series of speech and vowel samples from a prerecorded diverse set of 24 speakers representing a wide range of sex, age, fundamental frequency (F0), and voice quality types. Recordings were analyzed for the following measures: smoothed cepstral peak prominence (CPP in dB); the low vs high spectral ratio (L/H Ratio in dB); and the Cepstral Spectral Index of Dysphonia (CSID). ResultsA strong device effect was observed for L/H Ratio (dB) in both vowel and sentence contexts and for CSID in the sentence context. In contrast, device had a weak effect on CPP (dB), regardless of context. Recording distance was observed to have a small-to-moderate effect on measures of CPP and CSID but had a negligible effect on L/H Ratio. With the exception of L/H Ratio in the vowel context, setting was observed to have a strong effect on all three measures. While these aforementioned effects resulted in significant differences between measures obtained with SLM vs. smartphone devices, the intercorrelations of the measurements were extremely strong (r's > 0.90), indicating that all devices were able to capture the range of voice characteristics represented in the voice sample corpus. Regression modeling showed that acoustic measurements obtained from smartphone recordings could be successfully converted to comparable measurements obtained by a "gold standard" (precision SLM recordings conducted in a sound-treated booth at 15 cm) with small degrees of error. ConclusionsThese findings indicate that a variety of commonly available modern smartphones can be used to collect high quality voice recordings usable for informative acoustic analysis. While device, setting, and distance can have significant effects on acoustic measurements, these effects are predictable and can be accounted for using regression modeling.

EXPERIENCE OF USING ELECTRICAL TOMOGRAPHY, RADON SURVEY AND MICROSEISMIC SOUNDING IN SEARCH FOR PIPES CONTROLLED BY FAULT ZONES

The complex of geophysical methods was successfully applied in the Alakit-Markha kimberlite field of the Yakutsk diamondiferous province. A pipe was identified in the local forecast area specified within the field at the previous stage of prospecting. The studies using electric tomography (ET), radon survey (RS) and microseismic sounding (MS) covered an area of ≈1000⨯500 m. Based on the jointly processed ET and RS plan images and MS profiles, a tubular body was detected in the sedimentary cover. It is confined to a fault node and stands out among the host rocks by low electrical resistivity, increased soil radon concentrations and high spectral ratios of the horizontal and vertical components of microseisms. Its complex shape is manifested at the ground surface by two isometric structures (each being several hundred meters long), which jointly form a dike-like body at a depth of ≈40 m, as shown by the electrical tomography images. According to the MS data, its root part is detected to comprise one or two fractured narrow zones that are traceable to a depth of 2 km and below. The structure of the identified body and its chemical composition will be determined after exploratory drilling is complete. Today there are grounds to conclude that using ET, RS and MS methods jointly as a complex described in the article proved effective for identifying pipes controlled by fault zones in the sedimentary cover areas.

Use of cepstral analysis for differentiating dysphonic from normal voices in children

ObjectivesCepstral measures have mainly been evaluated by studies conducted on dysphonic and healthy adults, and many of these studies have reported the advantages of using cepstral measures for the evaluation of dysphonia however there is a paucity regarding to the cepstral analyses' results in dysphonic children. In this present study, it is hypothesized that cepstral peak prominence (CPP) and some other parameters of cepstral analysis would differ in children with vocal nodules when compared with the same parameters of cepstral analysis of healthy children. MethodsIn this present study, totally 54 children aged between 5 years old to 12 years and 7 months participated. The study group consisted of 20 males and 7 females diagnosed with vocal nodules. The control group consisted of an equal number of age- and gender-matched healthy peers. Analysis of Dysphonia in Speech and Voice software (CSL Model 4500 equipment, Kay Elemetrics Group) was used to gather speech sample recordings according to the Consensus Auditory-Perceptual Evaluation of Voice/Turkish protocol. Cepstral measures of all the six CAPE-V sentences and sustained/a/sample were calculated. CPP, CPP fundamental frequency, CPP standard deviation (CPP SD), Low_high spectral ratio (L/H ratio), L/H ratio standard deviation parameters were taken into account when statistical analyses were completed. In addition to the descriptive statistics of ceptral measures for both groups, the differences between the study and control groups according to the gender were documented. ResultsIt was found that for both genders CPP and CPP SD values were significantly higher for the control group for vowel-weighted sample, all voiced-weighted sample, glottal attack-weighted sample, nasal weighted sample, and voiceless-weighted sample. In the vowel-weighted sample, CPP and CPP SD were significantly higher for the control group in males. In females, a difference was only observed on the CPP parameter for the same sentence. In terms of the CPP value of the sustained phonation sample, a significant difference was only detected for males, whereas no difference was detected for females. ConclusionsIn conclusion, present study found that cepstral analysis can be used to determine the difference between dysphonic and healthy voices of children and indicated that cepstral analysis should be a compulsory component of routine clinical voice evaluation of children. In addition, this present study indicates that of the cepstral analysis of sentences appear to be more sensitive to dysphonia than the analysis of vowel samples. In future studies, normative values of the CAPE-V/Turkish sentences and cutoff values for differentiating dysphonia from normal voice should be evaluated using a larger sample size.

Dynamic Periods and Building Damage at Charleston, South Carolina during the 1886 Earthquake

Fundamental dynamic periods of Quaternary deposits beneath the peninsula of Charleston, South Carolina, are characterized spatially using an updated isopach map of Quaternary thickness, characteristic small-strain shear wave velocity information, a 1:24,000 geologic map, and a simple approximating equation. The updated isopach map is developed from subsurface information from 266 investigation sites. Estimates of fundamental periods for the Quaternary sediments primarily range between 0.3 and 0.7 s. These periods are lower end estimates of actual ground periods, based on a comparison with modeled response-spectra ratios. Estimates of fundamental periods range from 0.1 to 0.4 s for over 95% of the buildings present in 1886. Thus, the overlap between the range of building periods and the range in periods corresponding to high spectral ratios is not great. This finding agrees with the observation of Marciano and Elton that damage was independent (or only slightly dependent) of building height.