Acoustic reflex thresholds in young and elderly subjects with normal hearing

1981 ◽  
Vol 69 (1) ◽  
pp. 295-297 ◽  
Author(s):  
Stanley A. Gelfand ◽  
Neil Piper
Keyword(s):  
Normal Hearing ◽  
Elderly Subjects ◽  
Acoustic Reflex ◽  
Young And Elderly Subjects

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

3D gait assessment in young and elderly subjects using foot-worn inertial sensors

2010 ◽  
Vol 43 (15) ◽  
pp. 2999-3006 ◽  
Author(s):  
Benoit Mariani ◽  
Constanze Hoskovec ◽  
Stephane Rochat ◽  
Christophe Büla ◽  
Julien Penders ◽  
...  
Keyword(s):  
Inertial Sensors ◽  
Elderly Subjects ◽  
Gait Assessment ◽  
Young And Elderly Subjects

THE EXCRETION OF LARGE VITAMIN C LOADS IN YOUNG AND ELDERLY SUBJECTS: AN ASCORBIC ACID TOLERANCE TEST

1988 ◽  
Vol 17 (1) ◽  
pp. 35-41 ◽  
Author(s):  
R. J. NEALE ◽  
H. LIM ◽  
JULIE TURNER ◽  
C. FREEMAN ◽  
J. R. KEMM
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Acid Tolerance ◽  
Tolerance Test ◽  
Elderly Subjects ◽  
Young And Elderly Subjects

Age Effects on Measures of Auditory Duration Discrimination

1994 ◽  
Vol 37 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Peter J. Fitzgibbons ◽  
Sandra Gordon-Salant
Keyword(s):  
Hearing Loss ◽  
Stimulus Frequency ◽  
The Elderly ◽  
Duration Discrimination ◽  
Elderly Subjects ◽  
Hearing Sensitivity ◽  
Choice Procedure ◽  
Forced Choice Procedure ◽  
Tonal Stimuli ◽  
Young And Elderly Subjects

This study examined auditory temporal sensitivity in young adult and elderly listeners using psychophysical tasks that measured duration discrimination. Listeners in the experiments were divided into groups of young and elderly subjects with normal hearing sensitivity and with mild-to-moderate sloping sensorineural hearing loss. Temporal thresholds in all tasks were measured with an adaptive forced-choice procedure using tonal stimuli centered at 500 Hz and 4000 Hz. Difference limens for duration were measured for tone bursts (250 msec reference duration) and for silent intervals between tone bursts (250 msec and 6.4 msec reference durations). Results showed that the elderly listeners exhibited diminished duration discrimination for both tones and silent intervals when the reference duration was 250 msec. Hearing loss did not affect these results. Discrimination of the brief temporal gap (6.4 msec) was influenced by age and hearing loss, but these effects were not consistent across all listeners. Effects of stimulus frequency were not evident for most of the duration discrimination conditions.

The Prediction of Hearing Loss in Persons With Cerebral Palsy Using Contralateral Acoustic Reflex Threshold for Broad-Band Noise

2003 ◽  
Vol 12 (2) ◽  
pp. 91-95
Author(s):  
Michele B. Emmer ◽  
Shlomo Silman
Keyword(s):  
Hearing Loss ◽  
Cerebral Palsy ◽  
Broad Band ◽  
Screening Method ◽  
Accurate Method ◽  
Normal Hearing ◽  
Acoustic Reflex ◽  
Band Noise ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold

The utility of R. Keith’s (1977) method of screening for hearing sensitivity using the contralateral acoustic-reflex threshold (ART) for broad-band noise (BBN) was tested in persons with cerebral palsy (CP). Three groups of participants were included in this prospective study. The first group comprised 20 normal-hearing individuals without CP whose results were used as normative data. The second group comprised 16 participants with normal hearing and CP. The third group comprised 22 participants with sensorineural hearing loss and CP. The results of this study indicate that Keith’s screening method employing ART for BBN can be used successfully in a population with multiple handicaps where a quick, inexpensive, readily available, and accurate method is needed.

Atrial natriuretic peptide suppresses osmostimulated vasopressin release in young and elderly humans

1991 ◽  
Vol 261 (2) ◽  
pp. E252-E256 ◽  
Author(s):  
B. A. Clark ◽  
D. Elahi ◽  
L. Fish ◽  
M. McAloon-Dyke ◽  
K. Davis ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Hypertonic Saline ◽  
Natriuretic Peptide ◽  
Serum Sodium ◽  
The Elderly ◽  
Sodium Concentration ◽  
Elderly Subjects ◽  
Vasopressin Release ◽  
Young And Elderly Subjects ◽  
Atrial Natriuretic

Atrial natriuretic peptide (ANP) may suppress vasopressin release, but the dynamics of this interaction as well as the influence of age have not been defined. We studied six or seven young (19-40 yr old) and seven elderly volunteers (65-83 yr old) under two circumstances: 1) after infusion of 5% saline (0.04 ml.kg-1.min-1) for 2 h and 2) after the same infusion given with simultaneous synthetic human ANP (0.05 micrograms.kg-1.min-1). Hypertonic saline alone produced a progressive rise in plasma vasopressin with increasing serum sodium. During hypertonic saline alone, vasopressin levels began to rise at an increment in serum sodium of 1.67 +/- 0.35 mM in the young and 1.43 +/- 0.32 mM in the elderly and rose linearly with increasing serum sodium. When ANP was infused with hypertonic saline (with peak ANP levels of approximately 1,000 pM), vasopressin levels began to rise at an increment in serum sodium of 4.43 +/- 0.67 mM in the young and 4.57 +/- 0.43 mM in the elderly (P less than 0.01 vs. saline alone). Furthermore, the vasopressin response for any given serum sodium was significantly reduced in both young and elderly subjects, resulting in a rightward displacement of the curve relating vasopressin response to sodium concentration (P less than 0.001). In conclusion, ANP not only suppresses vasopressin but raises the threshold for release of vasopressin in response to osmotic stimulation in both young and elderly individuals. High circulating ANP levels may be responsible in part for the suppression of vasopressin levels and water diuresis seen during states of volume expansion.

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