Biology subjects

Klump, G. M.

Publications and source records attributed to Klump, G. M..

4 recordsLinked to original sources

bioRxiv2025

Speech-in-noise discriminability after noise exposure: Insights from a gerbil model of acoustic trauma

Exposure to loud sounds can lead to hearing impairments. Speech comprehension, especially in the presence of background sounds, allegedly declines as a consequence of noise-induced hearing loss. However, the connection between noise overexposure and deteriorated speech-in-noise perception is not clear yet and potential underlying mechanisms are still under debate. This study investigates speech-in-noise discrimination in young-adult Mongolian gerbils before and after an acoustic trauma to reveal possible noise-induced changes in the perception of speech sounds and to examine the commonly suggested link between noise exposure and speech-in-noise perception difficulties. Nine young-adult gerbils were trained to discriminate a deviant consonant-vowel-consonant combination (CVC) or vowel-consonant-vowel combination (VCV) in a sequence of CVC or VCV standards, respectively. The logatomes were spoken by different speakers and masked by a steady-state speech-shaped noise. After the gerbils completed the behavioral baseline experiments, they underwent an acoustic trauma and collected data for the second time in the behavioral experiments. Applying multidimensional scaling, response latencies were used to generate perceptual maps reflecting the gerbils internal representations of the sounds pre- and post-trauma. To evaluate how the discrimination of vowels and consonants was altered after the acoustic trauma, changes in response latencies between phoneme pairs were investigated with regard to their articulatory features. Auditory brainstem responses were measured to assess peripheral auditory function. We found that the perceptual maps of vowels and consonants were very similar before and after noise exposure. Interestingly, the gerbils overall vowel discrimination ability was improved after the acoustic trauma, even though the gerbils suffered from noise-induced hearing loss. In contrast to the improvements in vowel discrimination, there were only minor changes in the gerbils ability to discriminate consonants. Moreover, the noise exposure showed a differential influence on the response latencies for vowel and consonant discriminations depending on the articulatory features of the specific phonemes.

neuroscience↗

bioRxiv2024

Speech-in-noise perception across the lifespan: A comparative study in Mongolian gerbils and humans

Many elderly listeners have difficulties with speech-in-noise perception, even if auditory thresholds in quiet are normal. The mechanisms underlying this compromised speech perception with age are still not understood. For identifying the physiological causes of these age-related speech perception difficulties, an appropriate animal model is needed enabling the use of invasive methods. In a comparative behavioral study, we used young-adult and quiet-aged Mongolian gerbils as well as young and elderly human subjects to investigate the age-related changes in speech-in-noise perception evaluating whether gerbils are an appropriate animal model for the age-related decline in speech-in-noise processing of human listeners. Gerbils and human subjects had to report a deviant consonant-vowel-consonant combination (CVC) or vowel-consonant-vowel combination (VCV) in a sequence of CVC or VCV standards, respectively. The logatomes were spoken by different speakers and masked by a steady-state speech-shaped noise. Response latencies were measured to generate perceptual maps employing multidimensional scaling, visualizing the subjects internal representation of the sounds. By analyzing response latencies for different types of vowels and consonants, we investigated whether aging had similar effects on speech-in-noise perception in gerbils compared to humans. For evaluating peripheral auditory function, auditory brainstem responses and audiograms were measured in gerbils and human subjects, respectively. We found that the overall phoneme discriminability in gerbils was independent of age, whereas consonant discriminability was declined in humans with age. Response latencies were generally longer in aged than in young gerbils and humans, respectively. Response latency patterns for the discrimination of different vowel or consonant types were different between species, but both gerbils and humans made use of the same articulatory features for phoneme discrimination. The species-specific response latency patterns were mostly unaffected by age across vowel types, while there were differential aging effects on the species-specific response latency patterns of different consonant types.

neuroscience↗

bioRxiv2024

Auditory perception and neural representation of temporal fine structure are impaired by age but not by cochlear synaptopathy

Age-related hearing loss is a complex phenomenon. The earliest-onset degenerative event is the gradual loss of neural connections between cochlea and auditory brainstem. To probe for perceptual deficits that might arise from this loss, cochlear synaptopathy was induced pharmacologically in young-adult gerbils, which were then tested in a challenging listening task for the perception of temporal fine structure. Treated gerbils behaved no differently than normal-hearing, young-adult animals. In contrast, old gerbils, which typically express many cochlear and central-neural pathologies, showed impaired perception. To probe for the underlying mechanisms, single-unit responses were obtained from the auditory nerve to the same test stimuli. Responses from old gerbils showed no impairment in temporal locking to the stimulus fine structure. However, responses were significantly more driven by slower temporal fluctuations of the stimulus envelope, suggesting that the central auditory system may be unable to extract the relevant information for discrimination from such altered inputs.

neuroscience↗

bioRxiv2021

Speech Sound Discrimination by Mongolian Gerbils

The present study establishes the Mongolian gerbil (Meriones unguiculatus) as a model for investigating the perception of human speech sounds. We report data on the discrimination of logatomes (CVCs1 - consonant-vowel-consonant combinations with outer consonants /b/, /d/, /s/ and /t/ and central vowels /a/, /a:/, /{varepsilon}/, /e:/, /I/, /i:/, /[o]/, /o:/, /[mho]/ and /u:/, VCVs2 - vowel-consonant-vowel combinations with outer vowels /a/, /I/ and /[mho]/ and central consonants /b/, /d/, /f/, /g/, /k/, /l/, /m/, /n/, /p/, /s/, /t/ and /v/) by young gerbils. Four young gerbils were trained to perform an oddball target detection paradigm in which they were required to discriminate a deviant CVC or VCV in a sequence of CVC or VCV standards, respectively. The experiments were performed with an ICRA-1 noise masker with speech-like spectral properties, and logatomes of multiple speakers were presented at various signal-to-noise ratios. Response latencies were measured to generate perceptual maps employing multidimensional scaling, which visualize the gerbils internal representations of the sounds. The dimensions of the perceptual maps were correlated to multiple phonetic features of the speech sounds for evaluating which features of vowels and consonants are most important for the discrimination. The perceptual representation of vowels and consonants in gerbils was similar to that of humans, although gerbils needed higher signal-to-noise ratios for the discrimination of speech sounds than humans. The gerbils discrimination of vowels depended on differences in the frequencies of the first and second formant determined by tongue height and position. Consonants were discriminated based on differences in combinations of their articulatory features. The similarities in the perception of logatomes by gerbils and humans renders the gerbil a suitable model for human speech sound discrimination. HighlightsO_LIPerceptual maps of vowels and consonants in Mongolian gerbils are derived C_LIO_LIGerbils perceive vowels and consonants in the same way as humans C_LIO_LIGerbils discriminate vowels based on frequency differences of the formants C_LIO_LIGerbils discriminate consonants based on differences in articulatory features C_LI

neuroscience↗