These sounds are produced in a very similar way. In order to produce both sounds, the child has to place their top teeth on the bottom lip and push out air. One difference between these sounds is that the /f/ sound is produced with the voice “off” and the /v/ sound is produced with the voice “on.” This simply means that your vocal folds vibrate for the /v/ sound but not for the /f/ sound. Children can feel the difference between voiced and unvoiced sound by placing their hand on their neck (near the Adam’s Apple area) and saying both sounds. The other difference is that these sounds are mastered at different ages. The /f/ sound should be expected around age 3 and 1/2, while the /v/ sound doesn’t come in until around age 5. Here are some techniques to producing each sound:
- /F/ is the fire hose sound. Most children (especially boys) are in love with fire trucks at this age. They also love to use imaginary play. Luckily, a fire hose and the /f/ sound have similar qualities. When my clients are having difficulty producing the /f/ sound, it’s generally due to placement and airflow issues. Using the “fire hose” metaphor helps defeat the airflow issue because most children will immediately hold a pretend hose and blow air from their mouth when you ask them to pretend to be a fire hose. Airflow, check! Now, all we need to work on is placement. This is a great time to grab the mirror and encourage correct articulator positioning. Show the child how the top teeth gently “bite” the bottom lip. See if they can mimic your funny face. Once the placement is on target, ask them to make the same “fire hose” noise. It might be difficult to coordinate both movements at first, but keep working. The mirror should help give visual cues to “bite” the bottom lip and you might need to remind the child to make a “quiet” fire hose noise rather than blow the house down! With some practice, these techniques should lead the child to an accurate /f/ sound. If reminders are needed to produce the /f/ sound, you can use the visual cue of the fire hose to prompt the sound. As always, remember the hierarchy! Don’t expect this sound to be automatically used in conversation with 100% accuracy. Work your way up–isolation, syllables, words, phrases, sentences, conversation.
- /V/ is the car sound. Well if your kid doesn’t love fire trucks, then I bet they love cars. The /v/ sound also has a great metaphor– “vroom”. Once the /f/ sound is mastered, you can begin to target the /v/ sound. As I mentioned before, one difference between /f/ and /v/ is the presence of voicing. The /v/ sound is produced with vibration so the child can feel the difference between the two sounds if they place their hand on their neck. Use a discrimination task to differentiate /f/ from /v/. Is fan or van produced with your voice on? Once a clear difference is understood, you can practice producing the /v/ sound with the voice “on.” If your child requires a reminder to turn on their voice, you can can pretend to drive a car to cue them to use their “vroom” sound. Don’t forget to use the hierarchy just like you did with /f/!