What semantic notions underlie 吳 (shouting) with 夨 (man with tilted head)? Reading 誤's etymology spurred me to read 吳's etymology. Shouting doesn't require you to tilt your head, so why was 夨  used? Why not just use 人? 


  Glyph origin
  
  Ideogrammic compound (會意): 口 (“mouth”) + 夨 (“man with tilted head”) – to speak loudly.
  
  Definitions
  
  
  † to speak loudly; to shout
  † big
  (historical) (～國) one of the Warring States
  (historical) (～國) Eastern Wu, one of the Three Kingdoms
  the territory those states held, around the Yangtze delta
  Wu; the Chinese dialects of that territory, including Suzhounese and Shanghainese
  
  ⇒ 吳語
  A surname​.
  
  吳作棟 / 吴作栋 [Min Nan]  ―  Gô͘ Chok-tòng [Pe̍h-ōe-jī]  ―  Goh Chok Tong (Singapore's second Prime Minister; currently Emeritus Senior Minister)
  (～港) a harbor in Hiroshima Prefecture, Japan
This question is actually a good example of why Ancient Chinese scribes cannot keep on drawing pictures to represent words. They can avoid similar-looking or similar-meaning character components to a degree to distinguish between different words, but at some stage, it will become easier to incorporate a component which refers to the sound of a word rather purely relying on the meaning of a word.

Person (人) + mouth (口) has already been used for the character 「兄」.

商甲甲2292合集20014今楷　

Front view of a person (大, no tilted head) + mouth (口) has already been used for the following character:

商甲後2.18.7合集3028隸定