He punched her in the face twice, leaving her with a split lip, a bloody face and a broken tooth which required her to have dental work done.
Ms Pearson said Paku had a tenuous relationship with his neighbours but he had politely asked them to turn the music down as he had to get up early for training that morning.
She said the complainant had also advanced on Paku before he punched her. "He was not under the influence of alcohol but he said the two neighbours were."
Ms Pearson said Paku was a fulltime worker, a committed family man with six children, and he had pleaded guilty at the earliest opportunity.
Judge Pat Grace said while Paku was frustrated by the noise, according to the complainant, "the music was not that loud".
Judge Grace said the "fracas" was unacceptable.
"That sort of behaviour is not appropriate."
He convicted Paku on both charges and ordered him to pay reparations of $500 for emotional harm plus a $250 fine and court costs.