Summary: Temporal sound processing can be maintained in mouse models of congenital hearing loss with exposure to broadband sounds embedded with pauses, a new study reports.
Broadband sounds embedded with short pauses can maintain temporal sound processing in a mouse model of hearing loss, according to new research published in eNeuro.
Hearing loss treatments supplement auditory system function but don’t repair it. However a new intervention — playing broadband sounds during the onset of hearing loss — may be able to prevent the damage from ever occurring.
Augmented auditory environments have been able to preserve auditory processing of a wide range of sound frequencies in mice models.
In a new study, Dziorny et al. modified the traditional paradigm and preserved the processing of time-related, or temporal, sound features which are vital for understanding speech.
The research team exposed mice with congenital hearing loss to traditional augmented auditory environment, and a new one with almost undetectable gaps of silence. After 12 hours of exposure per day for 20 to 22 days, the team tested the animals’ response to sound in their brainstems, cochleas, and midbrains.
Both interventions preserved sound processing function in all three areas compared to mice that didn’t receive treatment. They also prevented hair cells from dying. But the version with gaps went even further: it maintained the ability to process temporal qualities of sounds.
Augmented auditory environments show promise as non-invasive intervention to minimize the effects of congenital hearing loss.
About this auditory neuroscience research news
Source: SfN Contact: Calli McMurray – SfN Image: The image is credited to Dziorny et al., eNeuro 2021
Rescuing auditory temporal processing with a novel augmented acoustic environment in an animal model of congenital hearing loss
Congenital sensorineural hearing loss (SNHL) affects thousands of infants each year and results in significant delays in speech and language development. Previous studies have shown that early exposure to a simple augmented acoustic environment (AAE) can limit the effects of progressive SNHL on hearing sensitivity. However, SNHL is also accompanied by hearing loss that is not assessed on standard audiological exams, such as reduced temporal processing acuity.
To assess whether sound therapy may improve these deficits, a mouse model of congenital SNHL was exposed to simple or temporally complex AAE. The DBA/2J mouse strain develops rapid, base to apex, progressive sensorineural hearing loss (SNHL) beginning at birth and is functionally deaf by 6 months of age.
Hearing sensitivity and auditory brainstem function was measured using otoacoustic emissions, auditory brainstem response and extracellular recording from the inferior colliculus in mice following exposure to 60 days of continuous AAE and in unexposed control mice. Peripheral function and sound sensitivity in auditory midbrain neurons improved following exposure to both types of AAE.
However, exposure to a novel, temporally complex AAE more strongly improved a measure of temporal processing acuity, neural gap-in-noise detection in the auditory midbrain.
These experiments suggest that targeted sound therapy may be harnessed to improve hearing outcomes for children suffering from congenital SNHL.