eng:to start talking or singing
yue:佢一開聲我就知道係佢啦。 (keoi5 jat1 hoi1 seng1 ngo5 zau6 zi1 dou3 hai6 keoi5 laa1.)
eng:I know it's him once he starts talking.
eng:to speak up; to voice out (to express concern or to support someone, etc.)
yue:#開到聲 (hoi1 dou3 seng1)
eng:to say something explicitly
yue:佢終於開聲支持自己老婆。 (keoi5 zung1 jyu1 hoi1 seng1 zi1 ci4 zi6 gei2 lou5 po4.)
eng:Finally, he speaks up for his wife.
yue:開着電子#裝置 嘅#響聲 或者#音量
eng:to turn on the ringtone or volume of a device
yue:有咩就打字啦，返工唔可以開聲。 (jau5 me1 zau6 daa2 zi6 laa1, faan1 gung1 m4 ho2 ji5 hoi1 seng1.)
eng:Type it out if you have anything to say. I can't turn on the volume during working hours.
yue:佢電話唔開聲，成日揾佢唔到。 (keoi5 din6 waa2 m4 hoi1 seng1, seng4 jat6 wan2 keoi5 m4 dou2.)
eng:His phone is always on silent mode and therefore he is always unreachable.
eng:vocal warm-up, an pre-performance exercise to fine-tune one's vocal muscles
yue:如果唔開聲就上台，會唱得好難聽。 (jyu4 gwo2 m4 hoi1 seng1 zau6 soeng5 toi4, wui5 coeng3 dak1 hou2 naan4 teng1.)
eng:One's performance would be disastrous if he skipped his vocal warm-up.