Itʼs Monday again! Todayʼs entry will be short and sweet. Iʼll be talking about S/Z ratios. I am not an expert on voice nor would I ever pretend to be. Infact, I inwardly donʼt even feel competent to work with that impairment, although Iʼve attended training sessions from the best in our ﬁeld. When Iʼm screening a child, if I hear a suspected voice disorder I will literally cringe. That is my least favorite disorder, but we all have to deal with what comes our way.
Voice disorders make up a very small percentage of our case loads therefore we donʼt encounter them frequently. Sometimes we cannot readily recall the information we need in making our initial screening judgements. Remembering how to do obtain the S/Z rations may have slipped out minds, as well as what is acceptable, and when to refer, so here is a quick refresher on S/Z rations.
You will need a stopwatch to time the sound durations.
1.Ask the child to take a deep breath and produce the /s/ for as long as they can. (I demonstrate this) Record the number of seconds he was able to sustain the /s/.
2.Now ask the child to do the same thing but saying the /z/ sound and record that time.
3.Repeat the above steps until you have 3 samples of /s/ and of /z/.
4.Calculate the S/Z ration by dividing the longest /s/ that was produced by the longest /z/ that was produced.
Now that you have your calculation what does that tell you? In a nutshell, A NORMAL RATIO IS BETWEEN 0.6-1.4 If the child has a ratio greater than 1.4 refer to an ENT.
TIP: The length of time a person can sustain a sound varies according to their age:
7-10 years old should be able to sustain a sound for 8 seconds;
11-15 years old should be able to go 12 seconds;
16 - adult female about 15 seconds;
16 - adult males about 20 seconds.
NOTE: If the child canʼt sustain the sound for the appropriate length of time after several trials Iʼd want to rule out issues affecting breath support such as dysarthria.
The factual information in this blog came from this website:
Next Monday I want to address mastery guidelines for articulation and using them when making placement decisions. Enjoy your kids this week!