The Effects of Probe-Tone Frequency on the Acoustic-Reflex Growth Function

2003 ◽  
Vol 14 (02) ◽  
pp. 109-118 ◽  
Author(s):  
John J. Lutolf ◽  
Honor O'Malley ◽  
Shlomo Silman
Keyword(s):  
Correlation Coefficients ◽  
Growth Function ◽  
Acoustic Reflex ◽  
Tone Frequency ◽  
Probe Tone ◽  
Growth Functions ◽  
Polynomial Coefficients ◽  
Acoustic Reflexes ◽  
Pure Tones ◽  
High Frequency Probe

Acoustic-reflex growth functions (ARGFs) were obtained from 20 normal-hearing listeners, Contralateral acoustic reflexes (ARs) were elicited with pure tones of 2000 Hz. The magnitude of changes in static compliant susceptance (BA) and conductance (GA) were monitored with probe-tone frequencies of 226 Hz, 678 Hz and 1000 Hz. ARGFs were obtained with six combinations of probe-tone frequency/admittance component: 226 Hz BA, 226 Hz GA, 678 Hz BA, 678 Hz GA, 1000 Hz BA, and 1000 Hz GA. Peak conductance (GA) and susceptance (BA) ARs were largest within the 678 Hz GA and 1000 Hz BAARGFs, respectively. Among high-frequency probe tones, the patterns of AR growth were larger and less variable for the 678 Hz GA ARGF and the 1000 Hz BA ARGF as determined by the magnitude of their linear (b1) and quadratic (b2) polynomial coefficients and the value of their squared correlation coefficients (R2).

Tympanometric and Acoustic-Reflex Studies in Neonates

1985 ◽  
Vol 28 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Barbara H. Sprague ◽  
Terry L. Wiley ◽  
Robert Goldstein
Keyword(s):  
Broadband Noise ◽  
Acoustic Reflex ◽  
Probe Tone ◽  
Acoustic Reflexes ◽  
Probe Frequency ◽  
High Age ◽  
Normal Neonates ◽  
Age Change

Tympanograms and acoustic reflexes for a broadband noise and for a 1000-Hz tone were measured in normal neonates. Notched tympanograms were typical of neonatal ears for a 220-Hz probe tone. A single-peaked tympanogram was most characteristic for a probe frequency of 660 Hz. Ipsilateral and contralateral acoustic reflexes were present more frequently for a 660-Hz probe tone compared to a 220-Hz probe tone, but acoustic-reflex thresholds were not significantly different between probe tones. As with adults, acoustic-reflex thresholds for the noise were significantly lower than for the tone, and ipsilateral reflex thresholds were lower than contralateral reflex thresholds. Reliability of acoustic-reflex and tympanometric measures was high. Age change from 2 to 4 days had no significant effect on tympanometric or acoustic-reflex characteristics. There was no apparent relation between tympanometric pattern and acoustic-reflex characteristics.

scholarly journals Effect of age on acoustic reflex thresholds in neonates and infants with normal hearing

2021 ◽  
Vol 7 (5) ◽  
pp. 746
Author(s):  
Dipti Gupta ◽  
C. S. Vanaja
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Clinical Population ◽  
Repeated Measure ◽  
Acoustic Reflex ◽  
Probe Tone ◽  
Acoustic Reflexes ◽  
Newborn Hearing ◽  
Neonates And Infants ◽  
Effect Of Age

<p><strong>Background:</strong> High frequency (1000 Hz) probe tone holds substantial promise for carrying out acoustic reflexes in neonates and infants. A limited number of studies indicates that acoustic reflex thresholds (ART) also change significantly with age as the newborn hearing system matures. However, there is a need for obtaining more data before using it in a clinical population. The aim was to investigate effect of age of infants on ARTs. Effect of activator signal was also explored.  <strong></strong></p><p><strong>Methods:</strong> ARTs were monitored using a 1 kHz probe tone for the 500 Hz, 1 kHz, 2 kHz, and 4 kHz pure tone activators in neonates and infants in the age range of 6 to 8 weeks were analysed.</p><p><strong>Results</strong>: The mean ARTs for neonates were lower compared to infants. Results of repeated measure ANOVA showed that there was a statistically significant age effect. Also, ARTs for high frequency activator signals were significantly higher than the ARTs for low frequency signals.</p><p><strong>Conclusions:</strong> The acoustic reflexes can be elicited for 500, 1000, 2000, and 4000 Hz when monitored using a 1000 Hz probe tone. There is an effect of age and activator signal on the acoustic reflex threshold. The data obtained in the present study can serve as normative for 0-1-week neonates and 6-8-weeks infants.</p>

scholarly journals The Role of the Clinically Obtained Acoustic Reflex as a Research Tool for Subclinical Hearing Pathologies

2020 ◽  
Vol 24 ◽  
pp. 233121652097286
Author(s):  
Andrew Causon ◽  
Kevin J. Munro ◽  
Christopher J. Plack ◽  
Garreth Prendergast
Keyword(s):  
Middle Ear ◽  
Noise Exposure ◽  
Quantitative Measure ◽  
Auditory Function ◽  
Acoustic Reflex ◽  
Normal Range ◽  
Probe Tone ◽  
Growth Functions ◽  
Clinically Normal

The acoustic reflex (AR) shows promise as an objective test for the presence of cochlear synaptopathy in rodents. The AR has also been shown to be reduced in humans with tinnitus compared to those without. The aim of the present study was twofold: (a) to determine if AR strength (quantified as both threshold and growth) varied with lifetime noise exposure, and thus provided an estimate of the degree of synaptopathy and (b) to identify which factors should be considered when using the AR as a quantitative measure rather than just present/absent responses. AR thresholds and growth functions were measured using ipsilateral and contralateral, broadband and tonal elicitors in adults with normal hearing and varying levels of lifetime noise exposure. Only the clinical standard 226 Hz probe tone was used. AR threshold and growth were not related to lifetime noise exposure, suggesting that routine clinical AR measures are not a sensitive measure when investigating the effects of noise exposure in audiometrically normal listeners. Our secondary, exploratory analyses revealed that AR threshold and growth were significantly related to middle-ear compliance. Listeners with higher middle-ear compliance (though still in the clinically normal range) showed lower AR thresholds and steeper AR growth functions. Furthermore, there was a difference in middle-ear compliance between the sexes, with males showing higher middle-ear compliance values than females. Therefore, it may be necessary to factor middle-ear compliance values into any analysis that uses the AR as an estimate of auditory function.

Contralateral Acoustic-Reflex Growth Function in a Patient with a Cerebellar Tumor

1989 ◽  
Vol 54 (4) ◽  
pp. 505-509 ◽  
Author(s):  
Theodore Harrison ◽  
Shlomo Silman ◽  
Carol Ann Silverman
Keyword(s):  
Differential Diagnosis ◽  
Tympanic Membrane ◽  
Growth Function ◽  
Cerebellar Tumor ◽  
Acoustic Reflex ◽  
Growth Functions ◽  
Air Volume ◽  
The Right

The contralateral acoustic-reflex growth functions (ARGFs) for 500-Hz and 1000-Hz tonal activators were obtained pre- and postsurgery in a patient with a right cerebellar tumor. The acoustic-reflex magnitude was quantified as the change in equivalent air volume at the tympanic membrane during acoustic-reflex contraction. The presurgical ARGFs were shallow in the right ear and steep in the left ear at both activator frequencies. The postsurgical ARGFs were steep, bilaterally, reflecting a return to normal in the right ear. The implications with respect to the use of the ARGF measure in differential diagnosis are discussed.

A Comparison of Acoustic Reflex and Loudness Growth in Normal and Pathological Ears

1973 ◽  
Vol 16 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Randall K. Beedle ◽  
Earl R. Harford
Keyword(s):  
Hearing Loss ◽  
Endolymphatic Hydrops ◽  
Growth Function ◽  
Unilateral Hearing Loss ◽  
Acoustic Reflex ◽  
Acoustic Reflexes ◽  
Reflex Threshold ◽  
Acoustic Reflex Threshold ◽  
The Relationship ◽  
Loudness Growth

This study compares acoustic reflex growth and loudness growth at 500, 1000, and 2000 Hz. Two groups of 10 subjects each were tested: a group with normal hearing, and a group with a unilateral hearing loss resulting from endolymphatic hydrops and demonstrating loudness recruitment. Acoustic reflexes were recorded graphically at successive 2-dB increments from the reflex threshold to a sensation level of 16 dB, employing an ascending and a descending approach. Alternate binaural loudness balances were performed at three sensation levels relative to the acoustic reflex threshold. Results indicate that the slope of the acoustic reflex growth function is much greater and more rapid for the normal ears than for either ear of the subjects with unilateral hydrops. Also, the acoustic reflex growth is essentially the same for the impaired ears and the good ears of the subjects with a unilateral hearing loss. On the basis of these results, it appears that the relationship presumed to exist between loudness experience and the acoustic reflex must be questioned.

A description of the growth of sheep

1998 ◽  
Vol 1998 ◽  
pp. 47-47
Author(s):  
R.M. Lewis ◽  
G.C. Emmans ◽  
G. Simm ◽  
W.S. Dingwall ◽  
J. FitzSimons
Keyword(s):  
Growth Curves ◽  
Growth Function ◽  
Single Equation ◽  
Rate Parameter ◽  
Growth Functions ◽  
Gompertz Equation ◽  
Lumped Parameter ◽  
Highly Correlated ◽  
Mature Size

The idea that an animal of a given kind has, and grows to, a final or mature size is a useful one and several equations have been proposed that describe such growth to maturity (Winsor, 1932; Parks, 1982; Taylor, 1982). The Gompertz is one of these growth functions and describes in a comparatively simple, single equation the sigmoidal pattern of growth. It has 3 parameters, only 2 of which are important - mature size A and the rate parameter B. Estimates of A and B, however, are highly correlated. Considering A and B as a lumped parameter (AB) may overcome this problem. A Gompertz, or any other, growth function is not expected to describe all growth curves. When the environment (e.g., feed, housing) is non-limiting, it may provide a useful and succinct description of growth. The objectives of this study were to examine: (i) if the Gompertz equation adequately describes the growth of two genotypes of sheep under conditions designed to be non-limiting; and, (ii) if the lumped parameter AB has more desirable properties for estimation than A and B separately.

Masking of Auditory Responses in the Medulla Oblongata of Goldfish

1973 ◽  
Vol 59 (2) ◽  
pp. 415-424
Author(s):  
PER S. ENGER
Keyword(s):  
White Noise ◽  
Background Noise ◽  
Nervous Activity ◽  
Band Width ◽  
Masking Effect ◽  
Noise Band ◽  
Octave Band ◽  
Tone Frequency ◽  
Centre Frequency ◽  
Pure Tones

1. The nervous activity of single auditory neurones in goldfish brain have been measured. 2. Four types of acoustic stimuli were used, (1) pure tones, (2) noise of one-third octave band width, (3) noise of one-octave band width with centre frequency equal to the pure tone, and (4) white noise. 3. Except for white noise, these stimuli produced the same response to equal sound pressures. The white noise response was less, presumably because the frequency range covered by a single neurone is far narrower than the range of white noise. 4. The conclusion has been reached that for low-frequency acoustic signals, the acoustic power over a frequency band of one to two octaves is integrated by the nervous system. 5. The masking effect of background noise on the acoustic threshold of single units to pure tones is strongest when the noise band has the same centre frequency as the test tone. In this case the tone threshold increases linearly with the background noise level. 6. When the noise band was centred at a different frequency from the tone, the masking effect decreased at a rate of 20-22 dB/octave for the first one-third octave for a tone frequency of 250 Hz. For a tone of 500 Hz the masking effect of lower frequencies was stronger and was reduced by only some 9 dB/octave for the first one-third octave.

scholarly journals One-dimensional game of life and its growth functions

1992 ◽  
Vol 15 (3) ◽  
pp. 499-508
Author(s):  
Mohammad H. Ahmadi
Keyword(s):  
Power Series ◽  
Rational Function ◽  
Formal Power Series ◽  
Infinite Product ◽  
Growth Function ◽  
The Other ◽  
Arbitrary Integer ◽  
One Dimensional ◽  
Growth Functions ◽  
Formal Power

We start with finitely many1's and possibly some0's in between. Then each entry in the other rows is obtained from the Base2sum of the two numbers diagonally above it in the preceding row. We may formulate the game as follows: Defined1,jrecursively for1, a non-negative integer, andjan arbitrary integer by the rules:d0,j={1     for   j=0,k         (I)0   or   1   for   0<j<kd0,j=0   for   j<0   or   j>k              (II)di+1,j=di,j+1(mod2)   for   i≥0.      (III)Now, if we interpret the number of1's in rowias the coefficientaiof a formal power series, then we obtain a growth function,f(x)=∑i=0∞aixi. It is interesting that there are cases for which this growth function factors into an infinite product of polynomials. Furthermore, we shall show that this power series never represents a rational function.

MONOID GROWTH FUNCTIONS FOR BRAID GROUPS

1991 ◽  
Vol 01 (02) ◽  
pp. 201-205 ◽  
Author(s):  
MARCUS BRAZIL
Keyword(s):  
Braid Group ◽  
Growth Function ◽  
Braid Groups ◽  
Growth Functions

It is shown that for all n, the braid group on n strings, Bn, has rational growth with respect to a certain set of elements of the group which generate it as a monoid. In particular, the precise growth function for B4 is calculated.

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