How to Pronounce the Voiceless or Soft "Th"

As the title suggests, the "th" sound can be voiced or voiceless. This means that the "th" sound can be made by an exhalation of air or with a vibration in the throat area.

The voiceless or soft "th" sound is made with an exhalation of air. You should not feel a vibration in your throat area. You should feel your tongue lightly touching your lower lips and 
in-between your teeth. So, it is as if you are lightly biting your tongue while at the same time touching your lower lip. With this formation, you make the voiceless or soft "th" by exhaling or blowing air through.

Things to remember:

1) Feel your tongue touching your lower lip.
2) Lightly bite your tongue with just enough pressure to allow air to pass through.
3) Blow air through your lip, tongue, and teeth formation to make the soft "th" sound.
3) The soft "th" is a voiceless sound so you should just use air to make the sound.
4) You should not vibrate your throat area to make the voiceless or soft "th" sound.

Here are some words you can practice with.

think	thought	fourth	fifth	southeast
thing	growth	athlete	depth	enthusiasm
through	authority	thin	wealth	thumb
three	truth	breath	worth	health-care
something	theory	theme	thirty	theology
month	throughout	thanks	athletic	bath
both	method	earth	math	therapist
nothing	mouth	thick	wealthy	seventh
anything	threat	ethnic	strengthen	northeast
health	through	Catholic	myth	thoroughly
everything	strength	forth	Catholic	thigh
death	faith	tooth	ethics	mathematics
thank	path	length	hypothesis	earthquake
north	worth	beneath	northwest	sympathy
third	threaten	therapy	ethical	aesthetic
south	youth	bathroom	monthly	booth
thousand	healthy	smooth	sixth	eighth
throw	birth	birthday	cloth	Thanksgiving
author	theater	throat	southwest	thread

You might also want to read my post of  Best way to practice the voiceless "th" sound.

Let me know your thoughts. Thanks.