https://tts.langeek.co/read?text=aG1t&hash=406ece0d4098c73e468b1a58d174d70d1e71d809&lang=en&cache-only=0&driver=googletts

https://tts.langeek.co/read?text=aG1t&hash=aa586f720bb07a13c9cf6875fcb8284c17370ebd&lang=en&cache-only=0&driver=googletts&accent=GB

These expressions are used in speech to fill the moments of hesitation of uncertainty or give the speaker time to gather their thoughts.