裏声 is read as うらごえ (uragoe) and means falsetto.
うらごえ
uragoe
こえがうらがえる
to crack (person's voice)
うらどおり
side street (often parallel to a main street)
うらぎる
to betray
うらぐち
backdoor
うらがえし
inside out
うらおもて
inside out (e.g. clothing)
うらがえす
to turn inside out
うらじ
land that does not adjoin to public or private roads
うらみち
unfair means
うらがね
bribe
うらがわ
the reverse (side)
うらづけ
support (e.g. for an argument)