Influence Of Auditory Experience Research Articles

Auditory Perceptual Abilities Are Associated with Specific Auditory Experience.

The extent to which auditory experience can shape general auditory perceptual abilities is still under constant debate. Some studies show that specific auditory expertise may have a general effect on auditory perceptual abilities, while others show a more limited influence, exhibited only in a relatively narrow range associated with the area of expertise. The current study addresses this issue by examining experience-dependent enhancement in perceptual abilities in the auditory domain. Three experiments were performed. In the first experiment, 12 pop and rock musicians and 15 non-musicians were tested in frequency discrimination (DLF), intensity discrimination, spectrum discrimination (DLS), and time discrimination (DLT). Results showed significant superiority of the musician group only for the DLF and DLT tasks, illuminating enhanced perceptual skills in the key features of pop music, in which miniscule changes in amplitude and spectrum are not critical to performance. The next two experiments attempted to differentiate between generalization and specificity in the influence of auditory experience, by comparing subgroups of specialists. First, seven guitar players and eight percussionists were tested in the DLF and DLT tasks that were found superior for musicians. Results showed superior abilities on the DLF task for guitar players, though no difference between the groups in DLT, demonstrating some dependency of auditory learning on the specific area of expertise. Subsequently, a third experiment was conducted, testing a possible influence of vowel density in native language on auditory perceptual abilities. Ten native speakers of German (a language characterized by a dense vowel system of 14 vowels), and 10 native speakers of Hebrew (characterized by a sparse vowel system of five vowels), were tested in a formant discrimination task. This is the linguistic equivalent of a DLS task. Results showed that German speakers had superior formant discrimination, demonstrating highly specific effects for auditory linguistic experience as well. Overall, results suggest that auditory superiority is associated with the specific auditory exposure.

Auditory experience and adult song plasticity.

Adults Bengalese finches normally sing stereotyped songs, which do not change under the influence of auditory experience. If deafened, however, adult birds sing significantly degraded songs that are characterized by a lack of stereotypy of syllable order and the deterioration of syllable structure. We studied the importance of auditory feedback for maintenance of normal adult song. Auditory feedback can be partially or completely removed by eliminating auditory hair cells, the sensory receptor cells for hearing. The effects are reversible because birds regenerate new hair cells when original cells are lost. Limiting the frequency range of auditory feedback available to birds using partial hair cell lesions indicated that low-frequency information (1500 Hz) is necessary and sufficient for the maintenance of normal adult song. Reversible deafening experiments using hair cell loss and regeneration indicated that adult Bengalese finches store memories of their own songs, which can be used to guide vocal behavior. Additionally, destabilizing song behavior by removing auditory feedback leads to renewed song plasticity, and some adults can be induced to learn new song. These studies suggest that Bengalese finches maintain normal song by comparing ongoing vocal output to stored models of their own stable songs and that neural circuitry for song learning persists beyond the sensitive period for song learning.

The Influence of Auditory Experience on the Fetus, Newborn, and Preterm Infant: Report of the Sound Study Group of the National Resource Center: The Physical and Developmental Environment of the High-Risk Infant

The Influence of Auditory Experience on the Fetus, Newborn, and Preterm Infant: Report of the Sound Study Group of the National Resource Center: The Physical and Developmental Environment of the High-Risk Infant

The influence of auditory experience on the behavior of preterm newborns.

This review of the research literature is addressed to clinicians who care for, interact with, and advise parents of preterm newborns. In summary, research on the effects of sound on preterm infant behavior and development provide only a little reliable clinical guidance as many of the studies are flawed, some badly. Some studies use a high sound level (i.e., loud) stimulus yet fail to report effects of the stimulus on vital signs, movement, and behavioral state. Only a handful of studies report long term effects regardless of the length of exposure to the experimental stimulus. A consistent problem is that the ambient sound in the nursery research setting is neither described nor considered as a facet of the auditory stimulus yet all reports of ambient nursery sound show high levels without respite periods of quiet. Therefore, unless other documentation is provided, ambient nursery noise is likely an unreported confounding variable in these studies. The clinician is cautioned, therefore, to carefully evaluate any finding before implementing an intervention program of sound stimulation with preterm infants. There are many reports of efforts to reduce nursery noise by changing staff behavior but none describes more than marginal success. Given this general failure of noise reduction through behavior change, an alternative is proposed of achieving quiet by changing the crowded, reverberant nature of the physical space. Recommendations for care that can be drawn from this literature include measuring and reducing nursery noise, facilitating parents' efforts to talk and sing to their own babies, and limiting purposefully added sound stimulation to quite specific clinical situations.

Influence of auditory experience on the development of brain stem auditory-evoked potentials in mallard duck embryos and hatchlings

The development of brain stem auditory-evoked potentials (BAEP) was studied in devocalized ducklings reared in auditory isolation and in vocal ducklings exposed to enhanced species-specific auditory stimulation with embryonic contact-contentment calls (CTs). Thresholds and latency of BAEP wave P1 in the mute ducklings indicated that even short-term auditory deprivation affected the development of auditory sensitivity, substantially reducing the rate of decline in BAEP thresholds and latencies of P1, especially in the low-frequency (500 and 750 Hz) and high-frequency (above 2.0 kHz) ranges. The ducklings exposed to enhanced stimulation, on the other hand, showed an accelerated decline in BAEP thresholds and latencies of P1 across all test frequencies, with the most marked influence on low (below 1.5 kHz) and high (above 2.5 kHz) frequencies. The influence of species-specific auditory experience had its most potent effect during the embryonic critical period for postnatal auditory perceptual (behavioral) development, at which time the embryo produces and hears a special low-frequency (1.5-2.5 kHz) version of its own contact-contentment vocalization.