I don't know what your key vocabulary is..., but this is your answer!!
When the amplitude of a sound wave increases, the intensity of the sound increases therefore the sound seems louder but does not change the pitch.
Therefore, if you increase the amplitude of the sound wave(s) of your cell phone ring, it will still sound the same yet louder.
For example, think of when you are increasing the volume on your phone... You are increasing the amplitude of your phone's speaker sound wave and whatever you were tuning in to would sound louder but would stay the same. It wouldn't go from a robot to a kitty sound now. Same concept happens when you decrease the volume on your phone yet this time you are decreasing the amplitude of a sound wave(s) and it gets softer.
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I hope that helps you out!!
Any more questions, please feel free to ask me and I will gladly help you out!!
