Fatigue effects of a pure tone and pure tones

1989 ◽  
Vol 86 (S1) ◽  
pp. S121-S121
Author(s):  
I. M. Young ◽  
L. D. Lowry
Keyword(s):  
Pure Tone ◽  
Pure Tones

Spread-of-Masking Effects on Pure Tones and Several Speech Stimuli

1973 ◽  
Vol 16 (3) ◽  
pp. 385-396
Author(s):  
Richard H. Wilson ◽  
Richard W. Stream ◽  
Donald D. Dirks
Keyword(s):  
Pure Tone ◽  
Narrow Band ◽  
Wide Band ◽  
Intensity Level ◽  
Speech Stimuli ◽  
Intensity Range ◽  
Speech Spectrum ◽  
Series Of Experiments ◽  
Pure Tones ◽  
Upper Slope

A series of experiments was performed to study the upward-spread-of-masking phenomena as it pertains to pure-tone and speech stimuli. In the initial two experiments, three maskers were employed over a 40–60-dB intensity range. They included a wide band (50–5500 Hz), a speech spectrum (50–1000 Hz), and a narrow-band (50–950 Hz) noise. All filter slopes were 48 dB/octave, except for the upper slope of the speech-spectrum noise that was 6 dB/octave. In the first experiment, pure-tone thresholds obtained by a tracking procedure revealed no spread of masking when the wide-band and speech-spectrum maskers were used. Substantial spread-of-masking effects, characterized by nonlinear threshold increments outside the spectrum of the masker, were observed with the narrow-band masker. The second experiment included three types of speech stimuli (PBs, spondees, and synthetic sentences) under the same mask conditions used with the pure tones. Threshold shifts observed for the wide- and speech-spectrum maskers were linear with the masking intensity level. However, increased shifts, attributable to spread of masking, were observed with the narrow band and progressed nonlinearly as a function of the masking level. Finally, two additional experiments, performed with two different narrow-band maskers and spondee words, provided insightful information regarding the effects of the spread of masking on speech stimuli.

Measurements of Multiple Pure Tone Propagation From a High Bypass Turbofan Rotor in an Internal Flow Facility

2020 ◽  
Author(s):  
Richard F. Bozak
Keyword(s):  
Pure Tone ◽  
Dynamic Pressure ◽  
Pressure Ratio ◽  
Internal Flow ◽  
Principal Component ◽  
Pressure Transducers ◽  
Acoustic Liners ◽  
Pure Tones ◽  
Dynamic Pressure Measurements ◽  
Stagger Angle

Abstract An important noise source in modern high bypass ratio turbofans is from multiple pure tones produced by the fan during takeoff. An experiment conducted on a 1.5 pressure ratio fan in an internal flow facility provided dynamic pressure measurements to investigate multiple pure tone generation and propagation. Since multiple pure tones are generated by blade shock variation primarily due to the fan’s blade stagger angle differences, the blade stagger angles were measured with an array of over-the-rotor dynamic pressure transducers. Multiple pure tone measurements were made with 30 wall-mounted dynamic pressure transducers from 0.4 to 1.1 diameters upstream of the rotor. Measured blade stagger angle differences correspond to the the shock amplitude variation measured upstream. The acoustic field was extracted from the dynamic pressure signals using principal component analysis as well as duct mode beamforming. Shocks traveling out the inlet were found to couple to duct modes propagating at similar angles. Over-the-rotor acoustic liners appear to reduce rotor shock variation resulting in a reduction of sub-harmonic multiple pure tone sound pressure levels by 3–4 dB.

Responses To Songs With Altered Tonal Quality By Adult Song Sparrows (Melospiza Melodia)

Behaviour ◽  
1996 ◽  
Vol 133 (3-4) ◽  
pp. 161-172 ◽  
Author(s):  
Stephen Nowicki ◽  
Jared Strote
Keyword(s):  
Adult Male ◽  
Distinctive Feature ◽  
Pure Tone ◽  
Playback Experiments ◽  
Perceptual Salience ◽  
Song Recognition ◽  
Song Sparrows ◽  
Sensitive Phase ◽  
Pure Tones

AbstractPure-tone sounds are a common and distinctive feature of many birdsongs. We used field playback experiments to test whether this tonal quality is perceptually salient to adult male song sparrows in the context of song recognition, by comparing responses to playback of normal songs with responses elicited by songs that had harmonics added. This species was chosen for study based on the recent finding that young song sparrows do not show a preference for songs with pure tones over songs with harmonics when choosing model songs to copy during their sensitive phase for learning. We found adult song sparrows to be significantly more responsive to normal song than to harmonic song, consistent with results from adult birds of other species. We conclude that the perceptual salience of the tonal quality of song changes during ontogeny or is context-dependent.

Paediatric hearing loss: a community-based survey in peri-urban Kumasi, Ghana

2019 ◽  
Vol 133 (09) ◽  
pp. 796-804
Author(s):  
R Larsen-Reindorf ◽  
E Otupiri ◽  
J E Anomah ◽  
B M Edwards ◽  
B Frimpong ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Pure Tone ◽  
Public Health Problem ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Community Based ◽  
Physical Finding ◽  
Cross Sectional ◽  
Pure Tones ◽  
Otoscopic Examination

AbstractBackgroundPaediatric hearing loss rates in Ghana are currently unknown.MethodsA cross-sectional study was conducted in peri-urban Kumasi, Ghana; children (aged 3–15 years) were recruited from randomly selected households. Selected children underwent otoscopic examination prior to in-community pure tone screening using the portable ShoeBox audiometer. The LittlEars auditory questionnaire was also administered to caregivers and parents.ResultsData were collected from 387 children. After conditioning, 362 children were screened using monaural pure tones presented at 25 dB. Twenty-five children could not be conditioned to behavioural audiometric screening. Eight children were referred based on audiometric screening results. Of those, four were identified as having hearing loss. Four children scored less than the maximum mark of 35 on the LittleEars questionnaire. Of those, three had hearing loss as identified through pure tone screening. The predominant physical finding on otoscopy was ear canal cerumen impaction.ConclusionPaediatric hearing loss is prevalent in Ghana, and should be treated as a public health problem warranting further evaluation and epidemiology characterisation.

Effect of contralateral pure tone stimulation on distortion emissions suggests a frequency-specific functioning of the efferent cochlear control

2012 ◽  
Vol 107 (7) ◽  
pp. 1962-1969 ◽  
Author(s):  
H. Althen ◽  
A. Wittekindt ◽  
B. Gaese ◽  
M. Kössl ◽  
C. Abel
Keyword(s):  
White Noise ◽  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Specific Effect ◽  
Outer Hair Cells ◽  
Efferent Activity ◽  
Distortion Product ◽  
Frequency Specificity ◽  
Olivocochlear System ◽  
Pure Tones

Contralateral acoustic stimulation (CAS) with white noise and pure tone stimuli was used to assess frequency specificity of efferent olivocochlear control of cochlear mechanics in the gerbil. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs), which are a byproduct of the nonlinear amplification by the outer hair cells. We used the quadratic DPOAE f2-f1 as ipsilateral probe, as it is known to be sensitive to efferent olivocochlear activity. White noise CAS, used to evoke efferent activity, had maximal effects on the DPOAE level for f2-stimulus frequencies of 5–7 kHz. The dominant effect during CAS was a DPOAE level increase of up to 13.5 dB. The frequency specificity of the olivocochlear system was evaluated by presenting pure tones (0.5–38 kHz) as contralateral stimuli to evoke efferent activity. Maximal DPOAE level changes were triggered by CAS frequencies close to the frequency of the DPOAE elicitor tones (tested f2 range: 2.5–15 kHz). The effective CAS frequency range covered 1.4–2.4 octaves and was centered 0.42 octaves below the DPOAE elicitor tone f2. The frequency-specific effect of CAS with pure tones suggests a dedicated central control of mechanical adjustments for peripheral frequency processing.

scholarly journals Methods used in mobile applications for the diagnosis of hearing loss: A systematic mapping study

2020 ◽  
Author(s):  
Atencio Vizcaíno Hebert Leonidas ◽  
Tintín Perdomo Verónica Paulina ◽  
Caiza Caizabuano José Rubén ◽  
Caicedo Altamirano Fernando Sebastián
Keyword(s):  
Health Care ◽  
Hearing Loss ◽  
Mobile Applications ◽  
Pure Tone ◽  
Measurement Methods ◽  
Diagnostic Methods ◽  
Systematic Mapping Study ◽  
Mapping Study ◽  
Systematic Mapping ◽  
Pure Tones

Hearing loss is one of the most common health problems today, it can appear at any age and the causes are varied, in order to prevent it or adapt to the changes brought about by the hearing impairment, it is necessary to diagnose it in time. The technology in terms of applications for health care smartphones has constantly evolved, so that today play an important role and are among the most downloaded from application stores, several of these applications are the diagnosis of hearing loss and use the method of pure tones. In this study a Systematic Mapping of Literature SMS (Systematic Mapping Study) is made to look for mobile applications that use other diagnostic methods that offer similar or better results, of the 13 applications found, 11 used the method of pure tones and in only 2 of them was implemented the speech audiometry (word recognition), concludes that diagnostic hearing loss tests based on mobile applications are reliable alternatives to conventional audiometric systems, and that pure tone thresholds alone are an incomplete assessment of hearing, and there is a need to develop new hearing measurement methods and combine them with other methods to complement the diagnosis. Resumen: La pérdida de la audición es uno de los problemas de salud más comunes en la actualidad, puede aparecer a cualquier edad y las causas son variadas, para poder prevenirla o adaptarse a los cambios que conlleva la deficiencia auditiva, es necesario diagnosticarla a tiempo. La tecnología en cuanto a aplicaciones para smartphones de asistencia de salud ha evolucionado constantemente, tal es así que hoy en día juegan un papel importante y son de las más descargadas de las tiendas de aplicaciones, varias de esas aplicaciones son las de diagnóstico de pérdida auditiva y utilizan el método de los tonos puros. En este estudio se hace un Mapeo Sistemático de Literatura SMS (Systematic Mapping Study) para buscar aplicaciones móviles que utilicen otros métodos de diagnóstico que ofrezcan similares o mejores resultados, de las 13 aplicaciones encontradas, 11 utilizaron el método de los tonos puros y en solo 2 de ellas se implementó la logoaudiometria (reconocimiento de palabras), por lo que se concluye que las pruebas de diagnóstico de pérdida auditiva basadas en aplicaciones móviles, son alternativas confiables a los sistemas de audiometría convencionales,  y que los umbrales de tonos puros por sí solos son una evaluación incompleta de la audición, y existe la necesidad de desarrollar nuevos métodos de medición de audición y combinarlos con otros métodos para complementar el diagnóstico.

ABR Results in Patients with Posterior Fossa Tumors and Normal Pure-Tone Hearing

1986 ◽  
Vol 94 (5) ◽  
pp. 568-573 ◽  
Author(s):  
Frank E. Musiek ◽  
Karen Kibbe-Michal ◽  
Nathan A. Geurkink ◽  
Anne Forrest Josey ◽  
Michael Glasscock
Keyword(s):  
Posterior Fossa ◽  
Pure Tone ◽  
Lesion Size ◽  
Auditory Brain Stem Response ◽  
Hearing Sensitivity ◽  
Select Group ◽  
Auditory Brain Stem ◽  
Pure Tones ◽  
Mass Lesions ◽  
Brain Stem Response

Sixteen patients with confirmed mass lesions of the posterior fossa and normal hearing sensitivity for pure tones were studied. Patients’ main symptoms, auditory brain-stem response (ABR), and lesion size were analyzed. All patients manifested neurologic and/or otoneurologic symptoms or complained of hearing difficulty disproportionate to their pure-tone findings. Interestingly, the patients in this select group were younger (mean = 34 years) than the typical patient with a posterior fossa tumor. ABR results were abnormal in 15 of the patients, although several indices—including absolute and interwave latencies, interaural latency difference, and wave presence/absence—were employed to achieve this sensitivity. Lesion size varied considerably and failed to correlate with ABR or pure-tone results.

scholarly journals Spectral response patterns of auditory cortex neurons to harmonic complex tones in alert monkey (Macaca mulatta)

1990 ◽  
Vol 64 (1) ◽  
pp. 282-298 ◽  
Author(s):  
D. W. Schwarz ◽  
R. W. Tomlinson
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Pure Tone ◽  
Response Pattern ◽  
Response Patterns ◽  
Neuronal Responses ◽  
Harmonic Complex ◽  
Tuning Curves ◽  
Complex Tones ◽  
Pure Tones

1. The auditory cortex in the superior temporal region of the alert rhesus monkey was explored for neuronal responses to pure and harmonic complex tones and noise. The monkeys had been previously trained to recognize the similarity between harmonic complex tones with and without fundamentals. Because this suggested that they could preceive the pitch of the lacking fundamental similarly to humans, we searched for neuronal responses relevant to this perception. 2. Combination-sensitive neurons that might explain pitch perception were not found in the surveyed cortical regions. Such neurons would exhibit similar responses to stimuli with similar periodicities but differing spectral compositions. The fact that no neuron with responses to a fundamental frequency responded also to a corresponding harmonic complex missing the fundamental indicates that cochlear distortion products at the fundamental may not have been responsible for missing fundamental-pitch perception in these monkeys. 3. Neuronal responses can be expressed as relatively simple filter functions. Neurons with excitatory response areas (tuning curves) displayed various inhibitory sidebands at lower and/or higher frequencies. Thus responses varied along a continuum of combined excitatory and inhibitory filter functions. 4. Five elementary response classes along this continuum are presented to illustrate the range of response patterns. 5. “Filter (F) neurons” had little or no inhibitory sidebands and responded well when any component of a complex tone entered its pure-tone receptive field. Bandwidths increased with intensity. Filter functions of these neurons were thus similar to cochlear nerve-fiber tuning curves. 6. ”High-resolution filter (HRF) neurons” displayed narrow tuning curves with narrowband widths that displayed little growth with intensity. Such cells were able to resolve up to the lowest seven components of harmonic complex tones as distinct responses. They also responded well to wideband stimuli. 7. “Fundamental (F0) neurons” displayed similar tuning bandwidths for pure tones and corresponding fundamentals of harmonic complexes. This response pattern was due to lower harmonic complexes. This response pattern was due to lower inhibitory sidebands. Thus these cells cannot respond to missing fundamentals of harmonic complexes. Only physically present components in the pure-tone receptive field would excite such neurons. 8. Cells with no or very weak responses to pure tones or other narrowband stimuli responded well to harmonic complexes or wideband noise.(ABSTRACT TRUNCATED AT 400 WORDS)

Children's Phonatory Matching of Pure-Tone and Human Voice Stimulus

1983 ◽  
Vol 14 (2) ◽  
pp. 75-78
Author(s):  
Carl R. Schneiderman ◽  
Elizabeth C. Somerville
Keyword(s):  
Statistical Analysis ◽  
Pure Tone ◽  
Human Voice ◽  
Wide Range ◽  
Pure Tones ◽  
Audio Oscillator ◽  
Age And Sex

Thirty-six children were tested for their ability to vocally match both human voice and pure-tone stimuli. Spectrographic and statistical analysis of their tape-recorded responses revealed the majority of the children more closely approximated the human voice stimulus. The effects of age and sex of the children on their ability to match the two types of stimuli were also examined. The results of this study indicate that children are better able to match audiotape recordings of trained human voices modeling a wide range of calibrated frequencies than pure tones generated by an audio-oscillator.

Summed Evoked Responses Using Pure-Tone Stimuli

1966 ◽  
Vol 9 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Geary A. McCandless ◽  
Lavar Best
Keyword(s):  
Pure Tone ◽  
Stimulus Frequency ◽  
Evoked Response ◽  
Evoked Responses ◽  
Response Patterns ◽  
Additional Advantage ◽  
Auditory Evoked Responses ◽  
Auditory Responses ◽  
Pure Tones ◽  
Major Consideration

Selected pure tones were used as stimuli in a study of evoked auditory responses in 25 adults. The effects of stimulus frequency, intensity, and duration on the evoked response were evaluated. Pure-tone stimuli appear to be as satisfactory as click stimuli in eliciting auditory evoked responses and have the additional advantage of providing more information relative to auditory function. Evoked response patterns were essentially the same for 500 Hz (cps), 2,000 Hz, and 4,000 Hz. Latencies were longer for the components of pure-tone-evoked responses than for click-evoked responses. Evoked responses may be influenced by (1) changes in stimulus parameters and (2) changes in subject’s psychophysical state. These variables become a major consideration in the recognition of the evoked response at intensity levels near threshold.

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