15$---> two part question

1. Discuss how hearing is affected by age. How are human factors professionals addressing these issues through research? Include details of the studies as a part of the discussion.

2. There are times where a siren can be heard but no vehicle can be seen and individuals have to locate the vehicle to ensure appropriate action be taken.

If you were to design a new and improved emergency siren that takes into account the aspects of sound (frequency, intensity, timbre, timing, etc.), describe what that siren would sound like. Discuss your recommendations for your choices based on pitch perception, sound localization and scene analysis.