What to listen for
"Dis" for "this" is the usual substitution and it is a placement error: D stops the air completely on the ridge behind the teeth, while voiced TH keeps it flowing with the tongue further forward. "Vat" for "that" and "brozer" for "brother" are the other two. If the tongue looks right and the sound is still wrong, it is the voicing — a voiced TH with the voice off is simply the TH in "think", so put a hand on the throat and check for the buzz. Watch the pressure as well: a hard bite locks the sound in place and makes "the" and "they" impossible at a natural speed.
Common Voiced TH errors
- Substituting /D/ for voiced /TH/ (e.g., "dis" for "this")
- Substituting /V/ for voiced /TH/ (e.g., "vat" for "that")
- Substituting /Z/ for voiced /TH/ (e.g., "brozer" for "brother")
- Turning the voice off, which produces the voiceless /TH/ in "think" instead
- Pressing the tongue too hard between the teeth, so the sound cannot release into the next vowel
How to run Voiced TH practice
Short and frequent beats long and occasional. Five to ten minutes on most days produces more correct Voiced TH productions over a fortnight than one long weekend session, and it is far easier to sustain.
Work in one position at a time. Get Voiced TH reliable at the beginning of words before moving to the middle and at the end — mixing all three from the start usually slows everything down.
Keep correction light. Model the word correctly and move on rather than asking for a repeat every time; a child who feels tested talks less, and less talking is the opposite of what Voiced TH practice needs.
Tips for the Voiced TH sound
- Have your child rest a hand on their throat while saying a long "thhhh." For this /TH/ they should feel a buzz; for the voiceless /TH/ in "think" they should feel nothing.
- Switch back and forth between "thigh" and "thy" — the only difference is the voicing, which makes it the quickest way to teach the contrast.
- Keep the tongue contact gentle. A hard bite locks the sound in place and makes "the" and "they" hard to say at a natural speed.
- Use a mirror so your child can see the tongue tip appear between the teeth rather than staying behind them.
- Practice the function words first — "the," "this," "that," "they," "them." They carry most of the voiced TH your child will ever say, so progress here is immediately audible.
- For "dis" for "this," contrast the two directly: /D/ stops the air completely with the tongue on the ridge behind the teeth, while voiced /TH/ lets it keep flowing with the tongue further forward.