Final answer:
In speech production, a voiceless fricative sound is produced by articulatory constriction that generates a continuous aperiodic sound.
Step-by-step explanation:
The source of sound for voiceless fricatives in the context of language and speech can be understood through the source-filter theory of speech production. Voiceless fricatives are produced by articulatory constriction where the flow of air is forced through a narrow passage in the vocal tract caused by the positioning of the articulators, such as the tongue or lips. Anatomically, this constriction acts as the source of a continuous aperiodic sound, generating turbulence that results in the characteristic fricative noise.
The source for a voiceless fricative is an articulatory constriction, which means there is an obstruction or narrowing of the airflow through the vocal tract. This constriction is created by the tongue, lips, teeth, or other articulators. The resulting sound is a continuous aperiodic sound, meaning it is a steady stream of turbulent noise without regular patterns.