Frequency Discrimination in Regions of Normal and Impaired Sensitivity

Background: There is a critical need for tests of auditory discrimination for young children as this skill plays a fundamental role in the development of speaking, prereading, reading, language, and more complex auditory processes. Frequency discrimination is important with regard to basic sensory processing affecting phonological processing, dyslexia, measurements of intelligence, auditory memory, Asperger syndrome, and specific language impairment. Purpose: This study was performed to determine the clinical feasibility of the Pitch Discrimination Test (PDT) to screen the preschool child’s ability to discriminate some of the acoustic demands of speech perception, primarily pitch discrimination, without linguistic content. The PDT used brief speech frequency tones to gather normative data from preschool children aged 3 to 5 yrs. Research Design: A cross-sectional study was used to gather data regarding the pitch discrimination abilities of a sample of typically developing preschool children, between 3 and 5 yrs of age. The PDT consists of ten trials using two pure tones of 100-msec duration each, and was administered in an AA or AB forced-choice response format. Study Sample: Data from 90 typically developing preschool children between the ages of 3 and 5 yrs were used to provide normative data. Data Analysis: Nonparametric Mann–Whitney U-testing was used to examine the effects of age as a continuous variable on pitch discrimination. The Kruskal–Wallis test was used to determine the significance of age on performance on the PDT. Spearman rank was used to determine the correlation of age and performance on the PDT. Results: Pitch discrimination of brief tones improved significantly from age 3 yrs to age 4 yrs, as well as from age 3 yrs to the age 4- and 5-yrs group. Results indicated that between ages 3 and 4 yrs, children’s auditory discrimination of pitch improved on the PDT. The data showed that children can be screened for auditory discrimination of pitch beginning with age 4 yrs. Conclusions: The PDT proved to be a time efficient, feasible tool for a simple form of frequency discrimination screening in the preschool population before the age where other diagnostic tests of auditory processing disorders can be used.

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Task-dependent effects of nicotine treatment on auditory performance in young-adult and elderly human nonsmokers

Scientific Reports ◽

10.1038/s41598-021-92588-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shuping Sun ◽

Michelle R. Kapolowicz ◽

Matthew Richardson ◽

Raju Metherate ◽

Fan-Gang Zeng

Keyword(s):

Frequency Modulation ◽

Auditory Processing ◽

Frequency Discrimination ◽

Normal Hearing ◽

Post Treatment ◽

Intensity Discrimination ◽

Modulation Identification ◽

Baseline Performance ◽

Auditory Performance ◽

Pre Treatment

AbstractElectrophysiological studies show that nicotine enhances neural responses to characteristic frequency stimuli. Previous behavioral studies partially corroborate these findings in young adults, showing that nicotine selectively enhances auditory processing in difficult listening conditions. The present work extended previous work to include both young and older adults and assessed the nicotine effect on sound frequency and intensity discrimination. Hypotheses were that nicotine improves auditory performance and that the degree of improvement is inversely proportional to baseline performance. Young (19–23 years old) normal-hearing nonsmokers and elderly (61–80) nonsmokers with normal hearing between 500 and 2000 Hz received nicotine gum (6 mg) or placebo gum in a single-blind, randomized crossover design. Participants performed three experiments (frequency discrimination, frequency modulation identification, and intensity discrimination) before and after treatment. The perceptual differences were analyzed between pre- and post-treatment, as well as between post-treatment nicotine and placebo conditions as a function of pre-treatment baseline performance. Compared to pre-treatment performance, nicotine significantly improved frequency discrimination. Compared to placebo, nicotine significantly improved performance for intensity discrimination, and the improvement was more pronounced in the elderly with lower baseline performance. Nicotine had no effect on frequency modulation identification. Nicotine effects are task-dependent, reflecting possible interplays of subjects, tasks and neural mechanisms.

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Evaluation of working memory in relation to cochlear implant consonant speech discrimination

The Egyptian Journal of Otolaryngology ◽

10.1186/s43163-021-00078-w ◽

2021 ◽

Vol 37 (1) ◽

Author(s):

Mai M. El Ghazaly ◽

Mona I. Mourad ◽

Nesrine H. Hamouda ◽

Mohamed A. Talaat

Keyword(s):

Working Memory ◽

Speech Perception ◽

High Frequency ◽

Word List ◽

Frequency Discrimination ◽

Frequency Resolution ◽

Speech Discrimination ◽

Place Of Articulation ◽

Strong Positive Relationship ◽

Speech And Language Development

Abstract Background Speech perception in cochlear implants (CI) is affected by frequency resolution, exposure time, and working memory. Frequency discrimination is especially difficult in CI. Working memory is important for speech and language development and is expected to contribute to the vast variability in CI speech reception and expression outcome. The aim of this study is to evaluate CI patients’ consonants discrimination that varies in voicing, manner, and place of articulation imparting differences in pitch, time, and intensity, and also to evaluate working memory status and its possible effect on consonant discrimination. Results Fifty-five CI patients were included in this study. Their aided thresholds were less than 40 dBHL. Consonant speech discrimination was assessed using Arabic consonant discrimination words. Working memory was assessed using Test of Memory and Learning-2 (TOMAL-2). Subjects were divided according to the onset of hearing loss into prelingual children and postlingual adults and teenagers. Consonant classes studied were fricatives, stops, nasals, and laterals. Performance on the high frequency CVC words was 64.23% ± 17.41 for prelinguals and 61.70% ± 14.47 for postlinguals. These scores were significantly lower than scores on phonetically balanced word list (PBWL) of 79.94% ± 12.69 for prelinguals and 80.80% ± 11.36 for postlinguals. The lowest scores were for the fricatives. Working memory scores were strongly and positively correlated with speech discrimination scores. Conclusions Consonant discrimination using high frequency weighted words can provide a realistic tool for assessment of CI speech perception. Working memory skills showed a strong positive relationship with speech discrimination abilities in CI.

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Hearing at threshold intensities: by slow mechanical traveling waves or by fast cochlear fluid pressure waves

Audiology Research ◽

10.4081/audiores.2020.233 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Haim Sohmer

Keyword(s):

Soft Tissue ◽

Hair Cells ◽

Traveling Wave ◽

Basilar Membrane ◽

Fluid Pressure ◽

Low Frequency ◽

Frequency Discrimination ◽

Outer Hair Cells ◽

Common Mechanism ◽

Frequency Stimulation

The three modes of auditory stimulation (air, bone and soft tissue conduction) at threshold intensities are thought to share a common excitation mechanism: the stimuli induce passive displacements of the basilar membrane propagating from the base to the apex (slow mechanical traveling wave), which activate the outer hair cells, producing active displacements, which sum with the passive displacements. However, theoretical analyses and modeling of cochlear mechanics provide indications that the slow mechanical basilar membrane traveling wave may not be able to excite the cochlea at threshold intensities with the frequency discrimination observed. These analyses are complemented by several independent lines of research results supporting the notion that cochlear excitation at threshold may not involve a passive traveling wave, and the fast cochlear fluid pressures may directly activate the outer hair cells: opening of the sealed inner ear in patients undergoing cochlear implantation is not accompanied by threshold elevations to low frequency stimulation which would be expected to result from opening the cochlea, reducing cochlear impedance, altering hydrodynamics. The magnitude of the passive displacements at threshold is negligible. Isolated outer hair cells in fluid display tuned mechanical motility to fluid pressures which likely act on stretch sensitive ion channels in the walls of the cells. Vibrations delivered to soft tissue body sites elicit hearing. Thus, based on theoretical and experimental evidence, the common mechanism eliciting hearing during threshold stimulation by air, bone and soft tissue conduction may involve the fast-cochlear fluid pressures which directly activate the outer hair cells.

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Effects of temporal fringes on fundamental-frequency discrimination

The Journal of the Acoustical Society of America ◽

10.1121/1.423975 ◽

1998 ◽

Vol 104 (5) ◽

pp. 3006-3018 ◽

Cited By ~ 28

Author(s):

Christophe Micheyl ◽

Robert P. Carlyon

Keyword(s):

Fundamental Frequency ◽

Frequency Discrimination

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The effects of contrast on visual orientation and spatial frequency discrimination: a comparison of single cells and behavior

Journal of Neurophysiology ◽

10.1152/jn.1987.57.3.773 ◽

1987 ◽

Vol 57 (3) ◽

pp. 773-786 ◽

Cited By ~ 186

Author(s):

B. C. Skottun ◽

A. Bradley ◽

G. Sclar ◽

I. Ohzawa ◽

R. D. Freeman

Keyword(s):

Spatial Frequency ◽

Striate Cortex ◽

Frequency Tuning ◽

Single Cells ◽

Frequency Discrimination ◽

Frequency Selectivity ◽

Response Amplitude ◽

Visual Orientation ◽

Characteristic Analysis ◽

Response Variance

We have compared the effects of contrast on human psychophysical orientation and spatial frequency discrimination thresholds and on the responses of individual neurons in the cat's striate cortex. Contrast has similar effects on orientation and spatial frequency discrimination: as contrast is increased above detection threshold, orientation and spatial frequency discrimination performance improves but reaches maximum levels at quite low contrasts. Further increases in contrast produce no further improvements in discrimination. We measured the effects of contrast on response amplitude, orientation and spatial frequency selectivity, and response variance of neurons in the cat's striate cortex. Orientation and spatial frequency selectivity vary little with contrast. Also, the ratio of response variance to response mean is unaffected by contrast. Although, in many cells, response amplitude increases approximately linearly with log contrast over most of the visible range, some cells show complete or partial saturation of response amplitude at medium contrasts. Therefore, some cells show a clear increase in slope of the orientation and spatial frequency tuning functions with increasing contrast, whereas in others the slopes reach maximum values at medium contrasts. Using receiver operating characteristic analysis, we estimated the minimum orientation and spatial frequency differences that can be signaled reliably as a response change by an individual cell. This analysis shows that, on average, the discrimination of orientation or spatial frequency improves with contrast at low contrasts more than at higher contrasts. Using the optimal stimulus for each cell, we estimated the contrast threshold of 48 neurons. Most cells had contrast thresholds below 5%. Thresholds were only slightly higher for nonoptimal stimuli. Therefore, increasing the contrast of sinusoidal gratings above approximately 10% will not produce large increases in the number of responding cells. The observed effects of contrast on the response characteristics of nonsaturating cortical cells do not appear consistent with the psychophysical results. Cells that reach their maximum response at low-to-medium contrasts may account for the contrast independence of psychophysical orientation and spatial frequency discrimination thresholds at medium and high contrasts.

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