In English, the voiceless "th" sound (/θ/) is a distinct phoneme that is used in words like "teeth" and "path." However, it's important to note that the pronunciation of the "th" sound can vary among native English speakers, and there can be some variation depending on regional accents or personal speech patterns.
In American English, it is common for the voiceless "th" sound to be pronounced as a dental fricative, represented by the "sss" sound you mentioned. This is the standard pronunciation and is generally considered correct. For example, "teeth" would typically be pronounced as "tee-ss" with the voiceless "th" sound.
However, it is also true that some native English speakers, including certain regional accents, may use different variations for the "th" sound. Some speakers may substitute it with a different sound, such as a "t" or an "f" sound. For example, "teeth" might be pronounced as "teet" or "teef" by some speakers.
These variations are considered nonstandard or dialectal, and they can be influenced by factors such as regional accents, speech patterns, or individual habits of pronunciation. It's important to note that these variations may not be universally understood or accepted in all English-speaking communities.
In summary, while the standard pronunciation of the voiceless "th" sound includes the "sss" sound, variations in its pronunciation do exist among native English speakers due to regional accents and personal speech patterns.