Are all sound waves periodic waves?

1. I am wondering what type of different sound waves there exists? Are all sound waves periodic waves, is there other types?

2. What does it mean when we put the word complex before a wave, like complex periodic wave?

I am new to physics and I've gotten confused about some terms and I would love it if someone could clarify them for me.

• An example of a sound wave that is not periodic : a sonar pulse. Used by submarines as well as bats (ultrasonic) for echolocating, the sonar pulse is a soliton sound wave, an isolated disturbance in the sound medium with no periodicity. – docscience Apr 2 '18 at 22:43

A function (a signal) is periodic in time when it repeats itself, when there is a period $T$ so that for all times $t$ it is valid that $f(t) = f(t + T).$
"Complex" can mean different things. It may refer to the representation as complex functions like $e^{i\omega t}.$ Or it may be a wave that is not a sine function with just one frequency.
• @HilulukAdde A tone has a pitch, a fundamental note with a certain frequency $f$. In general, the tone also contains harmonics (overtones) with frequencies $2f, 3f, ...,$ with amplitudes and phases that can be determined with Fourier integrals. – Pieter Apr 2 '18 at 19:59