Phase shift is the time difference or delay between two otherwise identical waveforms, typically expressed in degrees (°) or time units. When this shift occurs due to physical distance, it's often called path-length difference.

Phase is a measure of the position of a point in time on a waveform cycle. It describes the relationship between two or more waves of the same frequency, indicating how aligned or misaligned they are in time. Phase is typically measured in degrees, with a full cycle represented by 360°

Diffraction is the bending of waves around obstacles or through openings. It occurs when a wave encounters an obstacle or a gap that is comparable in size to its wavelength. The wave can bend around the edges of the obstacle or spread out after passing through an opening, reconstructing itself to some degree on the other side.

A reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. For sound waves, this occurs when the waves encounter a boundary that does not absorb all of the sound energy.

The wavelength of a sound wave is the physical distance between two consecutive points of the same phase in the wave, such as from one peak to the next peak, or from one trough to the next trough.

Velocity refers to the speed at which a sound wave propagates through a medium. In air, sound waves are longitudinal waves, meaning that the particles in the medium vibrate parallel to the direction that the wave is traveling in. The velocity of sound is determined by the properties of the medium it is traveling through.

Frequency refers to the number of times a sound wave repeats its cycle in a given time period, usually one second. A cycle is one complete repetition of the wave, starting from any point and returning to that same point. For example, if a soundwave repeats itself 440 times in one second, its frequency is 440Hz (Hertz).

Amplitude refers to the maximum displacement of a sound wave from its resting position (or centreline). In other words, it is the height of the wave’s peaks or the depth of it’s troughs. The greater the amplitude, the louder the sound.