What is the term for a wavelength that does not repeat and produces noise?

The term that describes a wavelength that does not repeat and produces noise is a complex wave. Complex waves consist of multiple frequencies and do not have a regular pattern, which is why they are often associated with noise. In contrast, a periodic wave has a consistent repeating pattern, which aligns with musical notes or tones rather than noise.

The fundamental refers to the lowest frequency of a wave, typically associated with musical pitch rather than noise, while harmonics are integer multiples of the fundamental frequency and also contribute to a tonal quality. Therefore, the best descriptor for a non-repeating waveform typically associated with noise is complex wave, highlighting the intricacies of sound waves that do not conform to a singular repeating rhythm.