The articulation-voice-fluency language aspects of talking require an active, ongoing auditory feedback system. In the normal speaker, an auditory model (such as repeating a sentence after someone) activates all the components of the speaking system (respiration, articulation, phonation, and resonance) in the proper sequential, overlapping order required to be phonologically accurate. In providing therapy for speech-language-voice handicapped people of all ages, the speech-language pathologist (SLP) frequently uses real-time auditory feedback and repeated auditory modeling. Some dysarthric and stuttering patients improve their speech by monitoring their rate of speech listening to a metronomic pacer. Sometimes, effective therapy requires degrading or altering the auditory feedback system, such as heard in delayed auditory feedback (DAF) or by using auditory masking.
Auditory feedback in therapy has been described extensively in the literature in different ways: speech-voice amplification, hearing oneself on immediate loop playback, DAF, masking, or employing a metronomic pacer to influence rate of speech. What Aronson (1985) has written about voice therapy has application to other forms of speech-language therapy:
Of major importance is instantaneous auditory feedback. What is singular about voice therapy is that in the early, critical stages, improved voice will break through suddenly and momentarily, milliseconds in duration; although the clinician may hear and identify these gains, the patient usually does not. Consequently, the clinician needs to listen carefully and, when the voice changes for the better or worse, communicate that information instantaneously to the patient (p. 336).
The KayPENTAX Facilitator, Model 3500, is an auditory feedback device that in one instrument offers amplification, looping, delayed auditory feedback, masking, and metronomic pacing. Such versatility of features enables the instrument to be used with many communication and learning problems, both diagnostically and in therapy-teaching situations. Its simple features make it ideal for use with children or adults. The Facilitator can be used in the clinic or its ready portability permits its effective use as a self-practice instrument out of the clinic, at home, at work, or in the classroom.
The ASHA Committee on Amplification for the Hearing Impaired (1991) has given recommendations for using amplification and auditory feedback to normal hearing people with such problems as "phonological disorders, central auditory processing disorders, and language/learning disabilities". Further, the Committee stated that the goals of such auditory feedback could include increasing attention span, reducing distractibility, improving signal-to-noise ratios, and increasing phonological awareness.
Auditory feedback may be provided by the KayPENTAX Facilitator, Model 3500, by using any one or all of these feedback options:
1. Real-time, focused speech-voice amplification with a pass band of 70–7800 Hz.
2. By use of two switches controlled by the clinician, auditory looping can be provided, playing back immediately what was just said. Loop-time may be up to 6 seconds in duration. Loops may be repeated once or as often as the clinician presses the STOP/PLAY switch.
3. Delayed auditory feedback may be added to real-time amplification, which can be set from .010 to 0.5 secs in increments of 10 msecs.
4. Speech range masking may be provided in both ears using band limited noise in the speech pass band. Using speech range masking permits masking at relatively lower intensities than most masking modes (e.g., white noise). Masking contains approximately 26 dB of level adjustment in 3 dB (or finer) adjustments. Masking can be either continuous or voice-activated. The Adjust button on the Facilitator allows the user to toggle between these two types of masking.
5. A metronomic pacer is available with 50-150 clicks per minute, available in 5 beats per minute increments.