Digital Audio Tape Recorder Research Articles

“The impact of orthognathic surgery on articulation proficiency and speech intelligibility in skeletal Class III malocclusion: 18 months follow up”

IntroductionOrthognathic surgery results in the positional change of the maxilla and mandible that may affect speech. The present study evaluated the effect of combined maxillary advancement and mandibular setback surgery on articulation proficiency and speech intelligibility in patients with non-syndromic skeletal Class III malocclusion. MethodsIn this prospective study, twenty-five patients with skeletal class III malocclusion and consecutively treated with Lefort-1 maxillary advancement and mandibular setback (BSSO) orthognathic surgery were included in this study. The speech sample was recorded with a digital audio tape recorder one day before surgery and at 3, 6, 9, 12 and 18 months after surgery. Three qualified and experienced speech and language pathologists evaluated articulation errors and intelligibility of speech samples. Repeated One-way analysis of variance was used to compare articulation proficiency and speech intelligibility at different time intervals. ResultsThe substitution, omission, distortion and addition errors showed no significant changes at 3 months and 6 months. The total articulation errors decreased to zero at 9 months and no significant increase was observed till 18 months (P < 0.05). Speech intelligibility showed statistically non-significant improvement at any time interval. Cephalometric skeletal parameters SNA and N ḻ A°. were significantly correlated with addition and total articulation errors at 18 months follow up. ConclusionsThe ortho-surgical treatment improves speech (decreases. articulation errors) in most of the patients usually 6–9 months post-surgery. Speech intelligibility is not affected by bimaxillary orthognathic surgery in skeletal class III patients. The articulation errors were correlated to changes in position of maxilla.

The soundscape of the southern Gulf of Mexico (Veracruz and Campeche)

The southern part of the Gulf of Mexico is a large area where little is known about its soundscape. We measured the environmental noise in Laguna de Términos, Campeche, México from 2004 to 2008 in stations distributed homogeneously in this lagoon during 17 sampling periods using a digital audio tape recorder sampling at 48 kHz with 16 bits for 1 min at each station. We also measured the environmental noise off Alvarado, Veracruz, México in June 2023 using a digital audio tape recorder sampling at 96 kHz with 24 bits for 50 min at four stations. The environmental noise in the recordings was measured with a semi-automatic MATLAB routine designed for this purpose. We will present preliminary results on the environmental noise in these two coastal locations using snapping shrimp sounds as a measure to depict differences in time and space within and between locations. Changes in submarine environmental noise are helping us in understanding the effects of natural phenomena and antropogenic sounds in the distribution and abundance of marine wildlife, such as snapping shrimps and bottlenose dolphins. [Work supported by CONACyT-Campeche, PAPIIT&amp;PASPA-UNAM, SMM, and UV.]

Imperfect Sound Forever

What is phonography? In this essay, Christopher DeLaurenti, a phonographer with three decades of experience, maps an axiomatic 13-lesson pedagogy through an abbreviated history of field recording, from Jesse Walter Fewkes in 1890 to Tony Schwartz in the early 1960s. This paper surveys various meanings and uses of the term phonography from a text published in 1701 to the formation in 2000 of the phonography listserv, an online community of makers of field recordings. The author, himself an early member of the phonography listserv, discusses three traits to define phonography as a community in the early 2000s: inexpensive recording equipment; a community of knowledge; and the “easy fidelity” made possible by portable and lightweight Digital Audio Tape (DAT) and MiniDisc (MD) recorders. The author contrasts the traits of phonography with elements of soundscape composition as articulated by Barry Truax, Hildegard Westerkamp, and Andra McCartney. The paper concludes by proposing possible elements of post-phonography, including remote control recording, the possibility of voice print identification, and the generation of unimagined data.

The flow and acoustic characteristics of underwater gas jets from large vertical exhaust nozzles

The flow and acoustic characteristics of underwater gas jets exhausted from large vertical nozzles are experimentally investigated in this work with gas flow rates of 30–150 m3/h, nozzle widths of d = 10 mm, 20 mm, 30 mm, and 40 mm. A high-speed digital video camera is used to examine bubble behavior and flow regimes. Sound pressure is measured by two hydrophones and recorded by a digital audio tape recorder. The audio and video signals are synchronized to find out the relationship between sound and gas behavior. Experimental results indicate that the general behavior of gas exhausted into water is of periodical necking and expansion. Sound pressure peaks are mostly excited by necking in two ways: pinch-off and redial expansion. Necking itself is a kind of low frequency behavior, corresponding to strong low frequency sounds. Moreover, necking can force the growing bubble to oscillate and emit broadband sound. As the gas velocity increases, necking would happen more frequently, and gas jets would grow into larger volume in shorter time, and then the sound radiated from the gas jets would have higher frequency and larger amplitude.

Snapping shrimp: Changes in environmental noise in Laguna de Términos, Campeche, México, after hurricanes

Laguna de Términos, Campeche, México, is one of the largest coastal lagoons in Mexico where snapping shrimp is the main source of biological sound. We measured the environmental noise from 2004 to 2008 in stations distributed homogeneously in this lagoon during 17 sampling periods using a digital audio tape recorder sampling at 48 kHz with 16 bits for 1 minute at each station. The environmental noise in the recordings was measured with a semi-automatic MATLAB routine designed for this purpose. Results indicate that environmental noise in the lagoon changes from one sampling to another, but it changed drastically after the hurricanes of 2005 in some of the stations. This changes in submarine environmental noise helps us in understanding the effects of natural phenomena in the distribution and abundance of marine wildlife, such as snapping shrimps and bottlenose dolphins. [Work supported by CONACyT-Campeche and PAPIIT&PASPA-UNAM.]

이유시기가 한우 송아지의 발성빈도에 미치는 영향

This study was conducted to investigate the effect of weaning period on the vocalization frequency of Hanwoo calf. Twelve Hanwoo calves were allocated into 4 groups, control (forced weaning on 90days) and treatment (weaning on 70, 90 and 120days with 5 adaptation days). After weaning, behavior and vocalization of Hanwoo calves were recorded on 3 consecutive days with closed circuit television (DTC-R5254, Digite Co., Ltd., Korea) and digital audio tape recorder (SR-900, Idamtech Co., Ltd., Korea). Vocalization frequency of Hanwoo calf were not significance difference with control and treatment group. Thus, additional studies of feed intake and body weight gain were needed to determine the weaning period of Hanwoo calves.

Evaluation of Selected Speech Parameters after Prosthesis Supply in Patients with Maxillary or Mandibular Defects

Background: Ablative surgery of oropharyngeal tumors frequently leads to defects in the speech organs, resulting in impairment of speech up to the point of unintelligibility. The aim of the present study was the assessment of selected parameters of speech with and without resection prostheses. Patients and Methods: The speech sounds of 22 patients suffering from maxillary and mandibular defects were recorded using a digital audio tape (DAT) recorder with and without resection prostheses. Evaluation of the resonance and the production of the sounds /s/, /sch/, and /ch/ was performed by 2 experienced speech therapists. Additionally, the patients completed a non-standardized questionnaire containing a linguistic self-assessment. Results: After prosthesis supply, the number of patients with rhinophonia aperta decreased from 7 to 2 while the number of patients with intelligible speech increased from 2 to 20. Correct production of the sounds /s/, /sch/, and /ch/ increased from 2 to 13 patients. A significant improvement of the evaluated parameters could be observed only in patients with maxillary defects. The linguistic self-assessment showed a higher satisfaction in patients with maxillary defects. Conclusion: In patients with maxillary defects due to ablative tumor surgery, an increase in speech performance and intelligibility is possible by supplying resection prostheses.

Sound production of two endemic Oedipodinae grasshoppers from the Iberian Peninsula: Jacobsiella imitans and Leptopternis candidus lusitanicus (Orthoptera: Acrididae)

In this study, which was conducted with captive specimens kept in wooden cages and separated by sex, the sounds produced by Jacobsiella imitans (Brunner, 1882) and Leptopternis candidus lusitanicus (Ebner, 1941) (Orthoptera, Acrididae) are described. Sounds were recorded with a digital audio tape recorder; the signal was digitized and then analysed with the Avisoft® software. Two types of sound, both produced by stridulation, were recorded in these species: an interaction song, produced when specimens are disturbed by others, and a courtship song, emitted by males when mounting another individual in trying to copulate. In both species, females are mute. Data concerning the time and frequency domains of these sounds are presented. The behaviour observed by both species in nature and that displayed when interacting with other individuals and during courtship are described. The role of song as an isolation mechanism is discussed.

Occupational and recreational noise exposures at stock car racing circuits: An exploratory survey of three professional race tracks

Noise in stock car racing is accepted as a normal occurrence but the exposure levels associated with the sport have not been adequately characterized. Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted an exploratory assessment of noise exposures to drivers, racing team members, and spectators at three stock car racing events. Sound level measurements were conducted using sound level meters, personal noise dosimeters, and a digital audio tape recorder that made sound recordings for later laboratory analysis. Area sound level measurements were made during race preparation, practice, qualification, and competition. Personal dosimetry measurements were conducted on drivers, team members, and spectators. Findings showed time-weighted averages (TWA) that ranged from A-weighted 96 decibels (dBA) for a spectator in the stands during a race to 114 dBA for a driver inside a car during practice. Peak sound pressure levels exceeded the maximum allowable limit of 140 dB during race competitions. Personal exposure measurements exceeded the NIOSH recommended exposure limit of 85 dBA as an 8-hr TWA in less than a minute for one driver during practice, within several minutes for team members, and less than one hour for spectators during the race. Hearing protection use was variable and intermittent among team members and spectators. Among drivers and team members, there was greater concern for communication performance than for hearing protection.

Bowhead whale springtime song off West Greenland

Three songs were recorded from bowhead whales (Balaena mysticetus) in Disko Bay, West Greenland, during 59 h of recordings via sonobuoys deployed on seven days between 5 and 14 April 2007. Song elements were defined by units following the protocol of previous description of bowhead whale song. The two most prominent songs were loud, complex, and repeated in long bouts on multiple recording days while the third song was much simpler and recorded on only one day. Bowhead whale simple calls and faint song elements were also recorded using digital audio tape recorders and a dipping hydrophone deployed from the sea ice approximately 100-150 km southwest of Disko Bay on three separate days suggesting that song is also produced in the central portion of Baffin Bay in winter. Songs recorded in Disko Bay are from an area where approximately 85% of the whales have been determined to be adult females. Although it is not known which sex was singing, we speculate that, as in humpback whales (Megaptera novaeangliae), male bowhead whales may sing to mediate sexual competition or mate selection behaviors. This is the first detailed description of springtime songs for bowhead whales in the eastern Arctic.

Child Voice and Noise: A Pilot Study of Noise in Day Cares and the Effects on 10 Children's Voice Quality According to Perceptual Evaluation

The purpose of this investigation was to study children's exposure to background noise at the ears during a normal day at the day care center and also to relate this to a perceptual evaluation of voice quality. Ten children, from three day care centers, with no history of hearing and speech problems or frequent infections were selected as subjects. A binaural recording technique was used with two microphones placed on both sides of the subject's head, at equal distance from the mouth. A portable digital audio tape (DAT) recorder (Sony TCD-D 100, Stockholm, Sweden) was attached to the subject's waist. Three recordings were made for each child during the day. Each recording was calibrated and started with three repetitions of three sentences containing only sonorants. The recording technique allowed separate analyses of the background noise level and of the sound pressure level (SPL) of each subjects' own voice. Results showed a mean background noise level for the three day care centers at 82.6dBA Leq, ranging from 81.5 to 83.6dBA Leq. Day care center no. 2 had the highest mean value and also the highest value at any separate recording session with a mean background noise level of 85.4dBA Leq during the noontime recordings. Perceptual evaluation showed that the children attending this day care center also received higher values on the following voice characteristics: hoarseness, breathiness, and hyperfunction. Girls increased their loudness level during the day, whereas for boys no such change could be observed.

Noise dosimeter for monitoring exposure to impulse noise

Commercially available noise dosimeters do not perform properly in impulsive noise environments because they suffer from instrumentation limitations and lack metrics that characterize impulse noise. In this paper, a design concept is proposed for an impulse noise monitoring dosimeter that addresses the current dosimeter’s limited capabilities and describes the various parameters that can appropriately be used to measure and evaluate exposure to impulse noise. The design concept is based on the accurate acquisition and storage of the original impulse waveform. For data analysis (using MATLAB) and calculation of “impulse noise metrics,” National Institute for Occupational Safety and Health (NIOSH) used a prototype impulse noise dosimeter system that consisted of a Bruel&Kjaer 4136 microphone and a Panasonic Digital Audio Tape Recorder. The proposed instrument would enable collection of data for validation of presently defined and yet to be defined metrics quantifying noise-induced permanent threshold shifts (NIPTS) resulting from impulse/impact exposures. It will also enable occupational safety and health professionals to make accurate measurements of ultimately approved metrics.

Limitations of Using Dosimeters in Impulse Noise Environments

The National Institute for Occupational Safety and Health (NIOSH) investigated the capabilities of noise dosimeters to measure personal exposure to impulse noise. The two leading types of commercially available dosimeters were evaluated in terms of their ability to measure and integrate impulses generated from gunfire during live-fire exercises at a law enforcement indoor firing range. Sound measurements were conducted throughout the firing range using dosimeters, sound level meters, and a measurement configuration that consisted of a quarter-inch microphone and a digital audiotape recorder to capture the impulse waveforms. Personal dosimetry was conducted on eight shooters, an observer, and the range master. Peak levels from gunfire reached 163 decibels (dB), exceeding the nominal input limit of the dosimeters. The dosimeters “clipped” the impulses by acting as if the gunfire had a maximum level of 146 dB. In other cases, however, peak levels (e.g., 108 dB) were below the dosimeter input limits, but the dosimeters still showed a peak level of 146 dB. Although NIOSH recommends that sound levels from 80 to 140 dB (A-weighted) be integrated in the calculation of dose and the time-weighted average, our present data suggest this criterion may be inadequate. These results showed that some instruments are incapable of providing accurate measures of impulse sounds because of their electroacoustic limitations.

Comparison of 3 bonded lingual appliances by auditive analysis and subjective assessment

The aim of this prospective study was to compare for the first time the influences of lingual appliances of different dimensions on sound performance and oral comfort. The study group comprised 12 subjects (10 women, 2 men; mean age, 33.96 years). Their sound production was recorded by means of a digital audio tape recorder before, 10 minutes after, and 24 hours after placement of the different appliances for semiobjective assessment by 3 blinded speech professionals. This was followed by supplementary subjective ratings of sound performance and oral comfort by the patients. All lingual appliances induced significant impairment in sound performance and oral comfort. However, they varied significantly with respect to the degree of impairment. The smaller the appliance, the less pronounced the impairments it induced. The smallest changes were induced by a bonded canine-to-canine retainer, followed by customized lingual brackets and prefabricated lingual brackets. By using lower-profile customized brackets, the orthodontist can significantly enhance patient comfort and significantly reduce impairments of sound performance in comparison with prefabricated brackets with larger dimensions. Before placing a lingual appliance, however, patients should be briefed on possible effects such as impaired sound production and decreased oral comfort.

Observation of very low frequency emissions at Indian Antarctic station, Maitri

Recently, we have succeeded in recording VLF emissions at the Indian Antarctic station, Maitri (geom. lat. 62°S, geom. long. 57.23°E,L = 45) using a T-type antenna, pre/main amplifiers and digital audio tape recorder. VLF hiss in the frequency ranges 11–13 kHz and 13–14.5 kHz and some riser-type emissions in the frequency range 3–5 kHz and magnetospheric lines at about 6.2, 8.0 and 9.2 kHz are reported for the first time. The generation and propagation mechanism of these emissions are discussed briefly.

Maturation and Release of Interleukin-1β by Lipopolysaccharide-primed Mouse Schwann Cells Require the Stimulation of P2X7 Receptors

The P2X7 receptor, mainly expressed by immune cells, is a ionotropic receptor activated by high concentration of extracellular ATP. It is involved in several processes relevant to immunomodulation and inflammation. Among these processes, the production of extracellular interleukin-1beta (IL-1beta), a pro-inflammatory cytokine, plays a major role in the activation of the cytokine network. We have investigated the role of P2X7 receptor and of an associated calcium-activated potassium conductance (BK channels) in IL-1beta maturation and releasing processes by Schwann cells. Lipopolysaccharide-primed Schwann cells synthesized large amounts of pro-IL-1beta but did not release detectable amounts of pro or mature IL-1beta. ATP on its own had no effect on the synthesis of pro-IL-1beta, but a co-treatment with lipopolysaccharide and ATP led to the maturation and the release of IL-1beta by Schwann cells. Both mechanisms were blocked by oxidized ATP. IL-1beta-converting enzyme (ICE), the caspase responsible for the maturation of pro-IL-1beta in IL-1beta, was activated by P2X7 receptor stimulation. The specific inhibition of ICE by the caspase inhibitor Ac-Tyr-Val-Ala-Asp-aldehyde blocked the maturation of IL-1beta. In searching for a link between the P2X7 receptor and the activation of ICE, we found that enhancing potassium efflux from Schwann cells upregulated the production of IL-1beta, while strongly reducing potassium efflux led to opposite effects. Blocking BK channels actually modulated IL-1beta release. Taken together, these results show that P2X7 receptor stimulation and associated BK channels, through the activation of ICE, leads to the maturation and the release of IL-1beta by immune-challenged Schwann cells.

Noise Exposure Assessment and Abatement Strategies at an Indoor Firing Range

Exposure to hazardous impulse noise is common during the firing of weapons at indoor firing ranges. The aims of this study were to characterize the impulse noise environment at a law enforcement firing range; document the insufficiencies found at the range from a health and safety standpoint; and provide noise abatement recommendations to reduce the overall health hazard to the auditory system. Ten shooters conducted a typical live-fire exercise using three different weapons--the Beretta.40 caliber pistol, the Remington.308 caliber shotgun, and the M4.223 caliber assault rifle. Measurements were obtained at 12 different positions throughout the firing range and adjacent areas using dosimeters and sound level meters. Personal and area measurements were recorded to a digital audio tape (DAT) recorder for further spectral analysis. Peak pressure levels inside the firing range reached 163 decibels (dB) in peak pressure. Equivalent sound levels (Leq) ranged from 78 decibels, A-weighted (dBA), in office area adjacent to the range to 122 dBA inside the range. Noise reductions from wall structures ranged from 29-44 dB. Noise abatement strategies ranged from simple noise control measures (such as sealing construction joints and leaks) to elaborate design modifications to eliminate structural-borne sounds using acoustical treatments. Further studies are needed to better characterize the effects of firing weapons in enclosed spaces on hearing and health in general.

Personal noise exposure assessment from small firearms

The National Institute for Occupational Safety and Health conducted noise exposure evaluations of law-enforcement personnel during firearms training at indoor and outdoor firing ranges. A representative cross section of weapons used by officers was measured. Shooters participated in live-fire exercise at an indoor firing range using three different weapons: a Beretta .400 caliber pistol, a Remington 12-gauge shotgun, and an M4 .223-caliber assault rifle. Indoor and outdoor measurements were obtained for the Smith and Wesson .357 pistol and Colt .450 and 9-mm pistols, the Glock .400 pistol, and the Heckler and Koch and Colt AR15 .223 rifles. Impulses were measured using a Bruel and Kjaer 4136 1/4-in. microphone and TASCAM digital audio tape recorder. Relevant impulse noise metrics were calculated. Peak levels ranged from 155 to 168 dB SPL. A-weighted equivalent levels ranged from 124 to 128 dBA. The contributions of the secondary weapon firings were approximately 1 to 9 dBA. Other parameters such as A/B durations, number and mixture of impulses, spectral content, energy, kurtosis, temporal spacing, and hearing protectors’ effectiveness were examined. Comparisons of applicable damage risk criteria are presented. Further studies are needed to establish an occupational impulse noise damage risk criterion.

Methods to study pre-school teachers' voice at work: simultaneous recordings with a voice accumulator and a DAT recorder

Long-term recordings with reliable methods are desirable for objective documentation of voice use during natural conditions. The purpose of this study was to evaluate a voice accumulator (VAC) with a digital audiotape (DAT) recorder as a reference. The VAC is based on a microprocessor that accumulates information about fundamental frequency (F0) and phonation time.A contact microphone attached to the front of the neck registers vocal fold vibrations. The DAT recorder was connected to two microphones for airborne signals placed at equal distance from the mouth close to the subject's ears. The computer program Aura was used to separate the subject's voicefrom the background noise. The Soundswell program was used for F0 andphonation time analysis. Two sets were performed: 1) One female speech-language pathologist was recorded with the two devices simultaneously in a sound-proof booth. She read a standard text with different voice qualities and sustained vowels with increasing F0 and intensity separately. The results showed good agreement between the two methods with respect to F0and phonation time. However, the VAC failed to register high frequencies above around 440 Hz as well as low intensities. 2) Three female pre-school teachers were recorded with the two devices simultaneously during a working day. Results showed high correlations between the two methods in terms of long-term measurements of F0 and phonation time for two subjects.For one subject with subcutaneous soft tissue on the neck, the registration with the contact microphone was not reliable. It was concluded that the VAC has the potential for assessment of occupational voice disorders if certain limitations of the method are considered.

Biosensing by insect olfactory receptor neurons

Action potentials of insect olfactory receptor neurons (ORN) were picked up with microelectrodes and amplified by a high-impedance amplifier connected to an oscilloscope, an audio amplifier, and an instrumentation amplifier. The amplified action potentials and odour exposure times were recorded on a DAT (digital audio tape) recorder for later analysis. This measurement of the stimulated action potential rates of the ORN of a blowfly ( Calliphora vicina) made it possible to estimate odour concentrations to which the ORNs of the antenna were exposed. Odours of 1,4-diaminobutane (14DAB), 1-hexanol (HX), and butanoic acid (BA) were used in the experiments to stimulate various ORNs, which discharged action potentials. Spontaneous and stimulated action potential rates were analysed by means of a time-to-voltage converter connected to a signal analyser. The estimated exposure concentrations of the 14DAB odour were between a few ppb (parts per billion) and about 100 ppm (parts per million) in air, those of BA odour between 20 ppm and almost 200 ppm, and those of HX odour about 8 ppm and 500 ppm. The 14DAB-sensitive ORN generated action potentials between 100 and 275 pps (pulses per second), the BA-sensitive ORN between 70 and 165 pps, and the HX-sensitive ORN between 115 and 300 pps. Higher exposure concentrations of each odour caused the cessation of action potential production because of adaptation and overloading of the sensor. This could be seen predominantly as a saturation of the corresponding ORN. The spontaneous action potential rate before, and after, each stimulus exposure was between 20 and 25 pps. Clean-air exposures typically sent action potentials at the same rate as the spontaneous activity of the ORN.