Question

When Mary talks, she creates an intensity level of 60 dB at your location. Alice talks with the same volume, also giving 60 dB at your location. If both Mary and Alice talk simultaneously from the same spot, what would be the new intensity level that you hear

Answer 1

When Mary and Alice talk simultaneously each at 60 dB, the resulting sound intensity level at the listener's location is approximately 63 dB because combining two sounds of the same intensity adds roughly 3 dB to the intensity level.

Step-by-step explanation:

When Mary and Alice both talk simultaneously, each creating an intensity level of 60 dB at your location from the same spot, the new intensity level that you hear does not simply add up to 120 dB. Instead, the combined intensity level is approximately 3 dB higher than the original level of one speaker due to the logarithmic nature of decibels. So, when both talk at the same time, the intensity level is approximately 63 dB.

According to the principle that a sound that is twice as intense as another is about 3 dB higher, when two sounds at 60 dB (with the same intensity) are combined, the resulting sound intensity level is 60 dB plus about 3 dB, which equals to roughly 63 dB.