Making Sounds

Sound is the name we give to any vibrations that we can detect withour ears.

Any vibrating object makes a 'sound'. This is because it makes the air particles near to it spread out and press closer together periodically - it makes the air particles vibrate. These vibrating particles pass energy on to neighbouring particles and in this way the sound propagates - moves along.

How we make sounds

When you breathe in and out, air quietly goes through the larynx. The larynx (voice box) does not make noise unless the vocal cords vibrate. Vocal cords are two muscles that are located inside the larynx. When you speak or makes a noise, the vocal cords vibrate as the you exhale. This vibration causes a sound wave.

A person can control the pitch of their voice, by making the vocal cords stretch at different lengths. A person does not conciously think about stretching his vocal cords when he speaks. Controlling vocal cords and changing the pitch of one's voice is learned as a small child - when you learned to talk. The noise made by the larynx combined with the shape of a persons mouth gives each person a unique sounding voice.

Speech sounds

Some speech sounds are made with the vocal cords vibrating. For example the sound 'z', as in the word zoo. Test it yourself. Put your fingers on your voice box and make a long 'zzzz' sound – like a bee buzzing. You can feel the vibration in your voice box through your fingers. This is because the vocal cords are moving.

Musical instruments:-

    • to make high pitched sounds you use short, thin strings or short pipes and vice versa.
    • to make loud notes you blow hard into wind instruments and pluck hard at string instruments.