The development of speech may have been the critical step in the development of the mind.In parallel with biological evolution,with the accumulation of gene differences,cultural evolution,the accumulation of experienc...The development of speech may have been the critical step in the development of the mind.In parallel with biological evolution,with the accumulation of gene differences,cultural evolution,the accumulation of experiences and ideas in symbolic form,began.Undoubtedly,the most significant stage of development is the development of the cerebral cortex.There are estimated one million cortical modules in each hemisphere.Sensory cells and sensory organs have well-determined centers,quasi“representative sites”in the brain;the stimuli of a sensory organ always flow into the corresponding center.The cortical projection of the main moving field is similar to the sensor field-a moving homunculus.Muscles involved in fine movements are represented over a larger area than muscles of other parts of the body.Remembering is a process of selection:only the memories that are important,interesting,significant for us are kept-the rest we forget.Speech,language,is central to the development of the ability to think and to the biological success of the human species.One of the most beautiful features of humankind is that they can live in a world of fantasy.They can imagine things they have never seen or never experienced.展开更多
Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing...Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing disorders, HHL happens when the cochlea (the peripheral auditory organ) is affected. There are several known risk factors to HHL which includes noise exposure, ototoxic drugs, and peripheral neuropathies, and age. Recent studies have shed light on this type of hearing loss, its etiology, prevalence, and how it can affect the auditory acuity in humans. Methods: This paper covers the current research regarding HHL, its causes, the different mechanisms involved in this disorder, and the diagnosis and potential treatments related to it. We will delve deeply into different researches concerning HHL. 4 articles from 285 were selected focusing on normal hearing individuals with bad speech intelligibility were discussed in this paper. In addition, articles discussing the effects of noise exposure on hearing impaired individuals were not considered as this study solely aims to focus on normal hearing sensitivity individuals with HHL, resulting in 4 articles from 285. Results: Numerous literatures over the decades have suggested that HHL is due to the degeneration of cochlear ribbon synapses, or hair cells synapses without hair cell damage. Their association with HHL was noted several times through this study, whether we were studying the effect of noise exposure, of age, or of ototoxicity. In all cases, no significant hair cell damage was observed, and normal thresholds were recovered. However, a decline in the amplitude of Auditory Brainstem Response (ABR) peak I from auditory nerve (AN) responses in noise exposed subjects and a decline in compound action potential (CAP) was measured when certain drugs were applied to the round window of Guinea pigs. Conclusion: Most studies, have proven that cochlear synaptophysin is the major contributor to noise induced, age, and ototoxic related HHL. There are several audiometric tests that were used to help identify HHL including Puretone audiometry in background noise, ABR, CAP, Distortion Product Otoacoustic Emission (DPOAE).展开更多
文摘The development of speech may have been the critical step in the development of the mind.In parallel with biological evolution,with the accumulation of gene differences,cultural evolution,the accumulation of experiences and ideas in symbolic form,began.Undoubtedly,the most significant stage of development is the development of the cerebral cortex.There are estimated one million cortical modules in each hemisphere.Sensory cells and sensory organs have well-determined centers,quasi“representative sites”in the brain;the stimuli of a sensory organ always flow into the corresponding center.The cortical projection of the main moving field is similar to the sensor field-a moving homunculus.Muscles involved in fine movements are represented over a larger area than muscles of other parts of the body.Remembering is a process of selection:only the memories that are important,interesting,significant for us are kept-the rest we forget.Speech,language,is central to the development of the ability to think and to the biological success of the human species.One of the most beautiful features of humankind is that they can live in a world of fantasy.They can imagine things they have never seen or never experienced.
文摘Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing disorders, HHL happens when the cochlea (the peripheral auditory organ) is affected. There are several known risk factors to HHL which includes noise exposure, ototoxic drugs, and peripheral neuropathies, and age. Recent studies have shed light on this type of hearing loss, its etiology, prevalence, and how it can affect the auditory acuity in humans. Methods: This paper covers the current research regarding HHL, its causes, the different mechanisms involved in this disorder, and the diagnosis and potential treatments related to it. We will delve deeply into different researches concerning HHL. 4 articles from 285 were selected focusing on normal hearing individuals with bad speech intelligibility were discussed in this paper. In addition, articles discussing the effects of noise exposure on hearing impaired individuals were not considered as this study solely aims to focus on normal hearing sensitivity individuals with HHL, resulting in 4 articles from 285. Results: Numerous literatures over the decades have suggested that HHL is due to the degeneration of cochlear ribbon synapses, or hair cells synapses without hair cell damage. Their association with HHL was noted several times through this study, whether we were studying the effect of noise exposure, of age, or of ototoxicity. In all cases, no significant hair cell damage was observed, and normal thresholds were recovered. However, a decline in the amplitude of Auditory Brainstem Response (ABR) peak I from auditory nerve (AN) responses in noise exposed subjects and a decline in compound action potential (CAP) was measured when certain drugs were applied to the round window of Guinea pigs. Conclusion: Most studies, have proven that cochlear synaptophysin is the major contributor to noise induced, age, and ototoxic related HHL. There are several audiometric tests that were used to help identify HHL including Puretone audiometry in background noise, ABR, CAP, Distortion Product Otoacoustic Emission (DPOAE).
