Effects of 100 dB SPL 8～16 kHz Octave Band Noise Exposure on Auditory Function in Mice
SHI Ke
LI Yueqi
WANG Jun
GUO Dan
Abstract：Objective To report effects of 100 dB SPL 8～16 kHz octave band noise exposure on hearing,cochlear hair cells and synapses in adult CBA/CaJ mice.Methods CBA/CaJ mice with normal hearing at 16 weeks of age were grouped to be exposed to 8～16 kHz octave noise at 100 dB SPL for 7.5,15,30,60 or 120 min(n=5～7 in each group).Auditory brainstem response(ABR)and distortion product otoacoustic emission(DPOAE)thresholds were assessed at 1 day and 14 days after exposure.The cochlear basilar membrane was isolated for immunofluorescence staining,with hair cells and synapses quantified using the Amira software.Results At 1 d after noise exposure,ABR and DPOAE thresholds were significantly elevated in all groups,which would have basically recovered to normal levels at 14 days after noise exposure.Immunofluorescence showed no inner and outer hair cells loss,but significant inner hair cells synapses loss in a noise dose-dependent manner and more severe in those exposed for 60 or 120 min(about 50%in the 32～45 kHz region).Conclusion Exposure to 8～16 kHz octave noise at 100 dB SPL for 7.5 min may be sufficient to cause hidden hearing loss in mice,especially at high frequencies.For short exposure,synaptic loss precedes the loss of sensory hair cells and represents an early manifestation of noise damage.
Keywords：octave noisetemporary threshold shiftcochleahidden hearing losscochlear synaptopathy
Publication Date：2025-10-20
Online Publishing Date：2025-10-17(First online date of this platform, not the publication date of the document)
Pages：6( 863-868 )