點解的士會有D好似對講機咁嘅聲嘅?

的士係有對講機，私人嘅有，公司嘅亦有，仲有六七部手機，你話巴唔巴閉呢﹗

Each taxi has a walkie talkie system.

The reason - it is the "official" way to request the dispatch of a taxi (Transport Department allows a surcharge for the dispatch).

Due to recent technology advancement, its usage has been dramatically decreased.