Apps and electronic devices

General information on apps and devices

These apps and devices are intended to help people who stammer produce more fluent speech.

They use a technology called Altered Auditory Feedback (AAF) to relay your voice back to you as you speak.


  • There are apps which can be used on a smartphone, tablet or computer. These are free or inexpensive.

Link to Apps...


BSA strongly recommends that, before purchasing an electronic fluency device, you try using an app (above), and seek an assessment from a speech and language therapist, to see if the device is likely to be suitable for you.

There are two main types of device:

  • Single-component device which fits in or around the ear, like a hearing aid.
  • Multi-component device: consisting of a box carried in the pocket, plus an earset and sometimes a separate microphone. The link from box to earset etc may be wireless, or through a wire. A wireless link makes the device less visible, more like a single component device.
  • Telephone assistive device

Link to Devices...

How do they work?

AAF apps and devices take advantage of the 'choral effect' - a phenomenon well-known to many people who stammer, who find that they can produce fluent speech when they talk in unison with other people. The app or device relays your voice back to you either with a slight delay (Delayed Auditory Feedback or DAF) or with a slight alteration in pitch (Frequency-shifted Auditory Feedback or FAF), or may use both of these techniques. The alterations appear to produce a similar effect to speaking alongside another person. For a theory why this may help, see Heidi and her altered auditory feedback device.

Some devices can also produce a hiss or buzz, which can be turned on to mask one's voice and help overcome a silent block (masking).

Using AAF

Some people find AAF helpful, and others do not.

If a person finds AAF useful, they may decide to use it mainly for more challenging situations, such as giving a speech.

A device can be used in conjunction with speech therapy - for example, to help you to practice techniques which previously were too difficult.

Can I get help with paying for one?

Remember that the apps and software are quite cheap. It is the devices that are more expensive.


NHS funding for such devices is not generally available.

Access to Work grants

If you are working, or wanting to start work, you may be able to obtain funding though the Access to Work scheme. You or your employer may need to pay part of the cost.

Jobcentre Plus policy at one stage was that they would not give Access to Work grants for fluency devices because they were medical equipment. However, following representations from the BSA, they have told us that they are now prepared to fund the devices for a trial period, following which they will review the situation again. In addition to the usual Access to Work eligibility criteria (see and our article Access to career), applicants will need to have an assessment by a speech and language therapist, and to have used a fluency device for a trial period.

If you have difficulties with the Access to Work application process, please let BSA know.

Example of claiming Access to Work: Access to career, Summer 2007.


Alternatively, if you are in work and you feel that a device would make a big difference to the way you do your job, it may be worth asking your employer if they could provide financial support for you to buy a device.

Disabled Students' Allowances

If you are a student, Disabled Students' Allowances may be available to fund a device. Official information and forms depend on where you normally live:

An example: Student allowance granted for fluency device - article from our magazine Speaking Out, Spring 2008.

Trying a device on loan

The supplier of a device may offer a trial period.