Objective To study effects of adenosine 5’-triphosphate (ATP) on cochlear function of guineapig. Methods After perfusion of ATP into perilymphatic spaces of the guinea pig cochlea, summating potential(SP) , cochlear ...Objective To study effects of adenosine 5’-triphosphate (ATP) on cochlear function of guineapig. Methods After perfusion of ATP into perilymphatic spaces of the guinea pig cochlea, summating potential(SP) , cochlear microphonic ( CM) , auditory nerve compound action potential ( CAP) , distortion product otoa-coustic emission (DPOAE) and auditory brainstem response (ABR) were measured. Results The resultsshowed concentration-dependent effect of ATP on the response alterations of bioelectric activity in cochlea. Adminis-tration of Immol/L ATP caused an increase both in the amplitude of the SP and in the threshold of ABR, a decreasein amplitude of the CAP and DPOAE. In addition, response alterations of the CAP and DPOAE showed in an inten-sity- and frequency-dependent manner, respectively. At levels of 20 - 70dB nHL sound intensity, lmmol/L ATPcaused a significant decrease in the CAP amplitude, while at moderate and high frequency ranges of 2 -8kHz it re-duced DPOAE amplitude significantly. 330μmol/L ATP also increased the threshold of ABR. Conclusion ATPthrough perilymphatic perfusion could inhibit cochlear function of guinea pig.展开更多
Mathematical models can be very useful for understanding complicated systems, and for testing algorithms through simulation that would be difficult or expensive to implement. This paper describes the proposal for a mo...Mathematical models can be very useful for understanding complicated systems, and for testing algorithms through simulation that would be difficult or expensive to implement. This paper describes the proposal for a model that would simulate the sound localization performance of profoundly hearing-impaired persons using bilateral cochlear implants (CIs). The expectation is that this model could be used as a tool that could prove useful in developing new signal processing algorithms for neural encoding strategies. The head related transfer function (HRTF) is a critical component of this model, and provides the base characteristics of head shadow, torso and pinna effects. This defines the temporal, intensity and spectral cues that are important to sound localization. This model was first developed to simulate normal hearing persons and validated against published literature on HRTFs and localization. The model was then further developed to account for the differences in the signal pathway of the CI user due to sound processing effects, and the microphone location versus ear canal acoustics. Finally, the localization error calculated from the model for CI users was compared to published localization data obtained from this population.展开更多
Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs...Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs)of young guinea pigs.Thus,it is essential to study the functioning of cochlear hair cells using DPOAEs in human newborn babies with maternal IDA.The current study explores maternal IDA’s effect on DPOAEs in newborn babies.Method:A total of 110 newborn babies with gestational age≥34 weeks were considered and a‘betweensubjects’design was used.The participants were divided into 3 groups-“Normal”(61 babies without maternal IDA),“Mild”(28 babies with mild maternal IDA)and“Moderate”(21 babies with moderate maternal IDA).The cord blood was collected and the DPOAEs were recorded for each baby for a range of frequencies(1 k 8 kHz)and a range of intensities(7040 dB SPL in 10 dB steps).Results:The analysis of both DP-gram and DP input-output(I/O)function showed that there was no significant difference(p>0.05)across the normal,mild,and moderate groups in the overall presence of DPOAEs as well as the amplitude across frequencies or intensities(7040 dB SPL).Also,the overall correlation of RBC indices with DPOAE amplitude across frequencies as well as the slope of the I/O function showed no relationship.Conclusion:The current study concludes that there is no effect of late-term maternal IDA on the DPOAEs of newborn babies.展开更多
基金Supported by National Natural Science Foundation of China (30100206).
文摘Objective To study effects of adenosine 5’-triphosphate (ATP) on cochlear function of guineapig. Methods After perfusion of ATP into perilymphatic spaces of the guinea pig cochlea, summating potential(SP) , cochlear microphonic ( CM) , auditory nerve compound action potential ( CAP) , distortion product otoa-coustic emission (DPOAE) and auditory brainstem response (ABR) were measured. Results The resultsshowed concentration-dependent effect of ATP on the response alterations of bioelectric activity in cochlea. Adminis-tration of Immol/L ATP caused an increase both in the amplitude of the SP and in the threshold of ABR, a decreasein amplitude of the CAP and DPOAE. In addition, response alterations of the CAP and DPOAE showed in an inten-sity- and frequency-dependent manner, respectively. At levels of 20 - 70dB nHL sound intensity, lmmol/L ATPcaused a significant decrease in the CAP amplitude, while at moderate and high frequency ranges of 2 -8kHz it re-duced DPOAE amplitude significantly. 330μmol/L ATP also increased the threshold of ABR. Conclusion ATPthrough perilymphatic perfusion could inhibit cochlear function of guinea pig.
文摘Mathematical models can be very useful for understanding complicated systems, and for testing algorithms through simulation that would be difficult or expensive to implement. This paper describes the proposal for a model that would simulate the sound localization performance of profoundly hearing-impaired persons using bilateral cochlear implants (CIs). The expectation is that this model could be used as a tool that could prove useful in developing new signal processing algorithms for neural encoding strategies. The head related transfer function (HRTF) is a critical component of this model, and provides the base characteristics of head shadow, torso and pinna effects. This defines the temporal, intensity and spectral cues that are important to sound localization. This model was first developed to simulate normal hearing persons and validated against published literature on HRTFs and localization. The model was then further developed to account for the differences in the signal pathway of the CI user due to sound processing effects, and the microphone location versus ear canal acoustics. Finally, the localization error calculated from the model for CI users was compared to published localization data obtained from this population.
文摘Background:Studies on animals have demonstrated that maternal iron deficiency anaemia(IDA)could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions(DPOAEs)of young guinea pigs.Thus,it is essential to study the functioning of cochlear hair cells using DPOAEs in human newborn babies with maternal IDA.The current study explores maternal IDA’s effect on DPOAEs in newborn babies.Method:A total of 110 newborn babies with gestational age≥34 weeks were considered and a‘betweensubjects’design was used.The participants were divided into 3 groups-“Normal”(61 babies without maternal IDA),“Mild”(28 babies with mild maternal IDA)and“Moderate”(21 babies with moderate maternal IDA).The cord blood was collected and the DPOAEs were recorded for each baby for a range of frequencies(1 k 8 kHz)and a range of intensities(7040 dB SPL in 10 dB steps).Results:The analysis of both DP-gram and DP input-output(I/O)function showed that there was no significant difference(p>0.05)across the normal,mild,and moderate groups in the overall presence of DPOAEs as well as the amplitude across frequencies or intensities(7040 dB SPL).Also,the overall correlation of RBC indices with DPOAE amplitude across frequencies as well as the slope of the I/O function showed no relationship.Conclusion:The current study concludes that there is no effect of late-term maternal IDA on the DPOAEs of newborn babies.
