Connecting the Microphone and Earphones

MPiStutter with Iasus NT3 throat microphone and monaural (one ear) earphone

MPiStutter with Iasus NT3 throat microphone and monaural (one ear) earphone

MPiStutter with Iasus NT3 throat microphone and Sony binaural (two ears) earphones

MPiStutter with Iasus NT3 throat microphone and Sony binaural (two ears) earphones with Headset Buddy 1-PC35-PH35 dual 3.5mm three-conductor to single 3.5mm four-conductor adapter.

MPiStutter with Iasus NT3 throat microphone, Sony binaural (two ear) earphones, and headphones for speech-language pathologist

MPiStutter with Iasus NT3 throat microphone, Sony binaural (two ear) earphones, and headphones for speech-language pathologist

Starting MPiStutter

Put on your throat microphone and earphones and start MPiStutter. The DAF is automatically switched on to help you adjust the microphone position. Start talking. When you hear your voice clearly click the "Ready" button.

Open the Settings screen. Adjust the microphone gain so that when you speak loudly the black line on the Real-Time screen representing vocal volume comes close to the top of the window, and when you stop talking the black line drops to the bottom of the window and the window goes white.

When you have the microphone gain adjusted, continue talking and you will see your phonation intervals color-coded:

  • Red, orange, and yellow indicate short phonation intervals.
  • Green indicates ideal phonation intervals.
  • Blue and purple indicate long phonation intervals.

Quitting MPiStutter

To quit MPiStutter, click your iPhone’s "Home" button to go to the home screen, then double-click the "Home" button to display the running apps. Hold your finger on any app until the red – dots appear in the upper-left corners of the running apps. Tap the red dot – on MPiStutter to shut it down.

Some customers ask why MPiStutter doesn’t have a “Quit” button. Apple requires that all apps quit the same way. Apple doesn’t allow “Quit” buttons.

7 Stages to Fluent Speech

Stage 1. Practice speaking slowly to produce all purple phonation intervals. Stretch your vowels until each syllable is a half-second or more long. Your speech will sound abnormally slow. Say one syllable at a time, with a pause between syllables, not between words. Hold each syllable equally. Many people mistakenly hold each word equally. E.g., at one half-second per syllable the phrase, “I am American” should take three seconds, not 1.5 seconds. I.e., this phrase sounds like “I am A-mer-i-can.” Practice this until you are 100% fluent with all purple syllables.

If you can’t do Stage 1: download our free e-book Fluency Shaping Stuttering Therapy: Techniques and Theory. Or watch our YouTube videos about fluency shaping:

Or see a speech-language pathologist who specializes in fluency shaping stuttering therapy.

Stage 2. Continue to stretch each syllable and say each syllable separately, but shorten each syllable to a quarter of a second. Practice this until you can get a screen with only blue intervals, and you are 100% fluent.

If you can’t do Stage 2: ask a comedian what the most important element of comedy is. Timing! Practice until you have better control of your syllable timing.

Stage 3. Say multi-syllable words normally, i.e., without pauses between syllables. Practice until you have all blue and purple phonation intervals, you are speaking at a "slow-normal" rate (i.e., a little slower than you usually talk but you sound normal), and you are 100% fluent. Relax your breathing and relax your vocal folds. You should hear your vocal volume and vocal pitch drop, i.e., the "sexy voice." In other words, in stages 1 and 2 you used the stretched syllable target, but in stage 3 you use two targets: stretched syllable and relaxed vocal folds.

If you can’t do Stage 3: try "two-handed stuttering therapy". Put one hand one your stomach. Breathe so that your hand moves out when you inhale, and in when you exhale. Notice that you’re taking smaller breaths more often. Your inhale and exhale times are equal. This is relaxed or diaphragmatic breathing. Now place the fingers of your other hand on your throat. Exhale and hum. Your fingers should feel a vibration. This is your vocal folds vibrating. Stop humming, and feel the vibration stop. Practice switching your phonation on and off. Vary your phonation in two ways. Change your volume (hum louder, then quieter). Change your pitch. Hum up and down a musical scale. With one hand on your stomach and your other hand on your throat, feeling diaphragmatic breathing and phonation, you should talk fluently. Now go to YouTube and watch some Barry White music videos. Pick one of his sexiest lines and practice it until you sound sexy.

Stage 4. Now you are ready to try for green phonation intervals. Drop the stretched syllable target and talk at a normal speaking rate. (If you use stretched syllables you will not produce green intervals.) Use only the relaxed breathing and relaxed vocal folds targets. Say multi-syllable words normally, i.e., without pauses between syllables. You should start to see green intervals.

If you can’t do Stage 4: relax your breathing and vocal folds and vary your speaking rate until you see green phonation intervals. Don’t expect to see all green phonation intervals, the goal is to produce some green phonation intervals. Normal speech won’t produce all green intervals. When you are speaking fluently at a normal speaking rate you will see a third or half green intervals, a third or quarter blue and purple intervals, and a third or quarter red, orange, and yellow intervals. In other words, normal speech produces a normal distribution or bell curve of phonation interval durations.

Stage 5. Go to the Evaluation screen and read the story aloud. Write down your speaking rate and percent short syllables. Read the story again and try to get a lower percent short syllables, at the same or faster speaking rate.

Stage 6. Restart MPiStutter to clear the Cumulative screen. Use MPiStutter in a conversation. This could be face-to-face or on the telephone. Then go to the Cumulative screen and write down your talk time and percent short syllables. Have another conversation and try to get the talk time longer and the percent short syllables lower.

If you can’t do Stage 6: because you don’t have anyone to talk to, watch an infomercial, call the toll-free number, and ask questions about the product in the infomercial.

Stage 7. Use MPiStutter all day, until you have at least two or three hours of talk time. At the end of every day write down your talk time and percent short syllables. The next day try to get your talk time longer and your percent short syllables lower.

If you can’t do Stage 7: because you don’t talk 2-3 hours per day, read our blog post about not talking enough. If you have a job, ask your supervisor to let you talk to customers. If you’re a student, talk more in class. If you have free time, do volunteer work that requires talking to people. If you have social phobia, see our blog post about speech-related fears and anxieties or seek treatment for social phobia. If you don’t want to talk 2-3 hours per day, MPiStutter may not be the best stuttering treatment for you. If you don’t like to talk and you just want a device to use when you need it, without thinking about it, get the SmallTalk.


Real-Time. You see the last four seconds of your speech in real time in the main window. Above the main window you see approximately the last ten minutes of your speech. In the upper screen try to make the green intervals tall and the red and orange intervals short. The number in the upper right corner of the Real-Time screen indicates the memory buffer. It should be zero or one or two digits. If it goes into the hundreds there will be a lag between when you talk and when you see your speech on the screen. With a 4th-generation or later iPhone or iPod touch buffering should not be a problem. Older devices may not be able to keep up with your speech.

Cumulative. This screen shows your phonation intervals since MPiStutter started. If you start MPiStutter in the morning and switch it off at night, the Cumulative screen shows how your speech for that day. The white clock shows your total speaking time for the day. The red clock shows your percent red or too-short intervals. Try to speak at least two or three hours each day, while trying to get the red number smaller every day.

Evaluation. This screen displays a story that has all the sounds of the English language. Click the "Start" button and start reading the story aloud. Scroll down and read to the end, then click "Stop." A normal speaking rate is 4 or 5 syllables per second. Try to get the % short intervals as low as you can.

Help. The help screen has these instructions.


Gain. Different microphones are more or less sensitive. Also, you may talk louder or quieter. The Iasus NT3 throat microphone should be set at 25. The throat accelerometer may need to be set to 0. A Bluetooth earset may need to be set to 100. Adjust the gain so that the black line indicating your vocal volume on the Real-Time screen goes to the top of the screen when you speak loudly but doesn’t "clip" or flatten at the top of the screen, and when you stop talking the black line drops to the bottom of the screen and the screen goes white.

Delayed Auditory Feedback (DAF). This has three settings. The default mode is "Voice Activated" mode. Your voice switches on the DAF, and it switches off when you stop talking. The other settings are "Off" and "Always On."

Minimum DAF Hold Time. This sets how long the DAF stays on for, after you speak too fast and the DAF switches on. The default is 2 seconds.

Delay length. 75 milliseconds (ms) is for a "slow-normal" speaking rate, that is, a little slower then normal speech but you don’t sound abnormally slow. 50 ms is for a normal or fast speaking rate. 100 ms and longer delays are only for abnormally slow speaking rates that are used in speech therapy. The 4th and 5th generation iOS devices have an additional 13 ms delay. If you want 75 ms delay then adjust this setting to 62 ms.

Analysis Time Period. The default is 2 seconds or half the screen, i.e., if too-short intervals appear in half of the main screen then the DAF switches on. To make this setting harder, increase this to 4 seconds or more. To make this setting easier, decrease this setting to 1 second.

Minimum Phonation Interval Duration. This sets what phonation intervals are too short. For most stutterers this is either 100 ms or 125 ms. Start at 100 ms. If you’re speaking fluently and DAF switches on only occasionally, and then switches itself off a few seconds later, then the Minimum Phonation Interval Duration is set correctly. But if you’re stuttering and the DAF doesn’t switch on, then adjust this setting harder, to 125ms or 150 ms. If you’re speaking fluently and the DAF is switching on too often, adjust this control easier, to 75 ms.

Required Interval Count. This is how many too-short intervals switch on the DAF. The default is 2 (in 2 seconds). To make this setting harder, change it to 1. To make this setting easier, change it to 3, 4, or 5.

Cut-Off Timing. If you use the Casa Futura Technologies accelerometer, set this at 30 ms. With the Iasus NT3 throat microphone, set this at 50 ms. The Iasus NT3 throat microphone picks up some false positives from breathing or movement in the 30-49ms range.