延音﹝意大利语：Fermata，意指停止﹞指将某一音符大幅度延长，但其延长的程度由演奏者决定，一般是音符的两倍。延音符号也可以加在休止符或小节线上，使音乐暂停。

延音早在15世纪便已出现。于巴洛克时期中，延音经常用以分隔不同的乐句，可供管乐演奏家换气。后来延音可用于乐章的不同部分，如在旋律当中。

在现今，一些作曲家除了使用半圆形的延音，也会使用其他如三角形、方形的延音，使音符延长的程度更具体，但此用法并未普及。

A fermata [ferˈmaːta] (also known as a hold, pause, colloquially a birdseye or cyclops eye, or as a grand pause when placed on a note or a rest) is a symbol of musical notation indicating that the note should be prolonged beyond its normal duration or note value would indicate. Exactly how much longer it is held is up to the discretion of the performer or conductor, but twice as long is not unusual. It is usually printed above, but occasionally below (upside down), the note that is to be held longer.