Question

t͡s Sounds like English cats, but in English this is a combination of two sounds: [ts]. Old Spanish used to have this sound, written ç or c: çielo, coraçon. Eventually, about 300 years ago it became [θ] in northern Spain and [s] in parts of southern Spain and in all of the the Americas.  It's typically written without the ligature on top and as a single unit symbol: [ʦ].

Accepted Answer

Voiceless Alveolar Affricate http://en.wikipedia.org/wiki/Voiceless_alveolar_affricate

Symbol	t͡s
Name	Voiceless Alveolar Affricate
Notes	Sounds like English cats, but in English this is a combination of two sounds: [ts]. Old Spanish used to have this sound, written ç or c: çielo, coraçon. Eventually, about 300 years ago it became [θ] in northern Spain and [s] in parts of southern Spain and in all of the the Americas. It's typically written without the ligature on top and as a single unit symbol: [ʦ].
Ref	http://en.wikipedia.org/wiki/Voiceless_alveolar_affricate

Alveolar Affricate English Written Spain T͡s Voiceless Sounds