An 8-week-old child is brought to an audiology clinic by the parents, who report that the child appears to respond only to very loud sounds. Both the birth and medical history are unremarkable, and there is no family history of hearing loss. Tympanograms are normal, and acoustic reflexes are present bilaterally at a screening level of 105 dB HL.

What additional steps should be taken to rule out a significant hearing loss?

To assess potential hearing loss in an infant, steps include performing otoacoustic emissions testing, auditory brainstem response testing, collaborating with a pediatric otolaryngologist, and conducting follow-up tests.

Explanation:

To rule out significant hearing loss in an 8-week old child who only responds to very loud sounds, the following additional steps should be taken:

Perform otoacoustic emissions (OAE) testing to assess the function of the outer hair cells in the cochlea.
Conduct auditory brainstem response (ABR) testing, which can give an estimate of hearing sensitivity without the need for voluntary responses.
Consider referral to a pediatric otolaryngologist for further evaluation and possible imaging studies to explore anatomical or neurological causes.
Follow up with repeat testing as the child matures, due to the dynamic nature of auditory development.

In this specific case, considering the presence of acoustic reflexes at screening level and normal tympanograms, OAE and ABR would be particularly indicative of cochlear and neural integrity, respectively.