<prompt> Boilers notch is suggestive of ?Conductive Hearing LossNoise Induced Hearing Loss NIHLBoth 1 and 2Normal Finding  <response>: Boiler notchAcoustic dip is seen in Noise induced hearing loss NIHL Boiler notch at 4000Hz Notch is seen in BC curve AC curve notch are insignificant Maximum seen at 3000-6000Hz Sound causing maximum NIHL 2000-3000Hz Stereocilia of Outer hair cells are first to be affected 