Question

The loudness or softness of a sound is determined basically by its amplitude its true or false

Answer 1

The statement is undoubtedly true.
The amplitude is defined as the magnitude of the maximum disturbance in the medium on either side of the mean value.
The loudness of sound is determined by it's amplitude. So, for a louder sound, it's amplitude must be high. The amplitude of the sound wave depends on the force with which an object is made to vibrate. For example, if we strike the table with less force, a sound which is produced will be of less energy (amplitude). So, we hear a soft sound. But if we strike the table forcefully, higher energy sound wave will be produced and as a result, we hear a loud sound. Thus amplitude is important while controlling and balancing the loudness of sound.
Hopefully this answer is helpful to you. Thanks.

Answer 2

The way the brain interprets the frequency of a sound emitted is called its pitch.  In order to produce “sounds of different pitch”, object of different sizes is needed, because it would vibrate at different frequencies.

It is True that “the amplitude of the sound wave depends upon the force with which an object is made to vibrate.” The amplitude and the loudness decreases as the sound moves away from its source.

For example, if a child is tapping on the floor slowly with a wooden stick, we hear a soft sound because less energy is used.  If the same child uses a steel plate and a wooden stick and hit it hard, making a loud sound, a higher energy is produced and as we could hear a loud sound.