Does Shanghainese have a buzzing sound & what does it mean? I overheard a Chinese man speaking over the telephone on the London underground last night. At one point he made a buzzing sound which in the context of his call I understood to be a word or at least a form of communication. If I was to write down the sound it would be a non-pinyin "ZZZZzzzzzZZZ" with the different cases a poor attempt at representing the variation in tone over the length of the sound.

My Chinese (Shandong) wife was with me and she believed that it was a word from what she calls (in English) 'local language' which she means to be any of China's non-standard Mandarin dialects or other languages excluding Cantonese.

After he finished the call we started a conversation because he was surprised to hear me speaking Chinese.  He told us he was from Shanghai. I didn't think at the time to ask him about that sound.

My wife believes it was a word from Shanghainese dialect but doesn't know the meaning. I believe this may be a word because I think I have heard similar sounds in a conversation between 2 Chinese people long ago before I knew any Chinese at all.

So, is this sound actually a word with a meaning from Shanghainese dialect? Or from any dialect at all?
是 (the copula) is pronounced /z̩/ in Shanghainese. The negative (often written as 伐, though for phonetic reasons only) is pronounced like "vah". So one often hears zzzvuhzzz in the middle of Shanghainese conversations.