Final answer:
A nurse should evaluate an 18-month-old toddler for hearing loss if the child has difficulty pronouncing certain consonant sounds, as it could indicate a hearing issue affecting language development.
Step-by-step explanation:
In assessing hearing development in toddlers, the nurse should identify that difficulty pronouncing certain consonant sounds could indicate a need to assess the toddler for hearing loss. By 18 months, many toddlers are capable of using one- to two-word phrases, responding to their name being called, and frequently putting objects in their mouths as part of exploring their environment. However, consistent difficulty articulating consonants can suggest possible hearing issues that might be impacting language development, thereby necessitating further evaluation for potential hearing impairment.