Final answer:
The minimum SPL at the pillow in sleeping areas should be loud enough to alert or wake a person. Typically, the requirement for alarms is around 75 dB, but the exact level can vary depending on the standards and regulations. No specific dB level is provided in the information given for this question.
Step-by-step explanation:
The question refers to the minimum Sound Pressure Level (SPL) required in sleeping areas, specifically at the pillow.
SPL is measured in decibels (dB), and the context of this question is centered around safety and health considerations regarding how loud alarms or notifications need to be in order to be effective while someone is sleeping.
Examining the information provided and understanding the relation between intensity levels and decibels, we can infer that sound at the pillow in sleeping areas should be loud enough to wake a person but not cause hearing damage.
No specific decibel level is provided in the information given, but generally, sleeping areas should be peaceful and not excessively loud.
Typically, sound level requirements for alarms are around 75 dB but this will vary depending on the regulations in place.
However, without explicit reference to standards or regulations in the question or the provided reference information, determining the exact minimum SPL just from the provided data is challenging.