How does amplitude relate to loudness perception?

How does amplitude relate to loudness perception?

• A. There is no relationship between amplitude and loudness.
• B. Loudness is determined solely by frequency, not amplitude.
• C. Greater amplitude leads to greater displacement of the basilar membrane, resulting in higher loudness perception.
• D. Loudness depends only on the ear's age.

Answer: (C)

Amplitude is the size of the pressure fluctuations in a sound wave. When amplitude is larger, the eardrum and ossicles move more, causing greater displacement of the basilar membrane. This bigger mechanical deflection bends the hair cell stereocilia more, opening more ion channels and increasing neurotransmitter release to the auditory nerve. The resulting neural activity is stronger, and the brain interprets that stronger signal as a louder sound. Frequency, by contrast, mainly determines pitch, while factors like age or sensitivity influence how we perceive loudness, but they don’t define it.

Amplitude is the size of the pressure fluctuations in a sound wave. When amplitude is larger, the eardrum and ossicles move more, causing greater displacement of the basilar membrane. This bigger mechanical deflection bends the hair cell stereocilia more, opening more ion channels and increasing neurotransmitter release to the auditory nerve. The resulting neural activity is stronger, and the brain interprets that stronger signal as a louder sound. Frequency, by contrast, mainly determines pitch, while factors like age or sensitivity influence how we perceive loudness, but they don’t define it.