Final answer:
A loudspeaker creates sound by vibrating its cone, producing oscillating air pressure waves. The loudness of these sound waves is measured in decibels, with higher amplitudes resulting in louder sounds. The human ear's sensitivity to frequencies also affects perceived loudness.
Step-by-step explanation:
A loudspeaker produces sound by oscillating its cone, which causes the air molecules around it to vibrate, creating changes in air pressure. This is illustrated in the scenario where a speaker is vibrating at a constant frequency and amplitude. These mechanical vibrations result in longitudinal pressure waves that move through the air, creating the sound we hear. The loudness of these sounds can be quantified in decibels (dB), where higher amplitude waves correspond to louder sounds. For instance, a loudspeaker can emit a 90.0-dB sound, which is quite intense, even if the speaker operates at low efficiency and requires minimal energy input.
The efficiency of a loudspeaker plays a significant role in determining the power input needed to produce a specific sound intensity level. A speaker with an efficiency of 1.00% and a diameter of 12.0 cm producing a 90.0-dB sound level would require a certain amount of power input. The calculation of this power input is based on the speaker's efficiency and the desired sound intensity level.
The human ear is sensitive to different frequencies of sound, with certain ranges of frequencies being perceived as louder due to greater sensitivity. Consequently, sounds at either extreme of the audible range, whether too high or too low in frequency, may be less easily heard compared to those within the optimal range for human hearing.