Fricative:

Two organs are brought and held sufficiently close together for the escaping air-stream to produce strong friction. This friction may or may not be accompanied by voice. The quality and intensity of fricative sounds varies greatly, but all are acoustically composed of energy at relatively high frequency.

/f, v/

The soft palate being raised and the nasal resonator shut off, the inner surface of the lower lip makes a light contact with the edge of the upper teeth, so that the escaping air produces friction.

/ θ, ð/

The soft palate being raised and the nasal resonator shut off, the tip of the tonge make a light contact with the edge and inner surface of the upper incisors and a firmer contact with the upper side teeth, so that the air escaping between the forward surface of the tongue and the indisors caused friction.

/s, z/

The tip and the blade of the tongue make a light contact with the upper alveolar ridge, and the side rims of the tongue a close contact with the upper teeth. The air-stream escapes by means of a narrow groove in the centre of the tongue and causes friction between the tongue and the alveolar ridge

/ ʃ, ʒ/

The tip and blade of the tongue make a light contact with the alveolar ridge, the front of the tongue being raised at the same time in the direction of the hard palate and the side rims of the tongue being in contact with the upper teeth.

/h/

The air is expelled from the lungs with considerable pressure, causing some friction throughout the vocal tract, the upper part of wich is shaped in readiness for the articulation of the following vowel