When the Facilitator is turned on, it functions as a speech-voice amplifier. The real-time amplification has a pass-band focus of 70–7800 Hz. Such amplification is designed to amplify primarily the speech-voice of either the clinician or the client/patient. The instrument was not designed as a hearing aid with the amplification of environmental sounds along with speech amplification. Rather, the microphone, earphones, and amplifier all offer an improved signal-to-noise ratio, permitting the Facilitator to be used for speech amplification purposes at relatively low and safe intensity levels.
Amplification of teaching models and the child’s spoken response have become important parts of many phonologic intervention programs. The use of real-time, low-level amplification appears to direct the client’s attention to the phonologic target. Normal hearing children with learning disabilities and/or attention span deficits are using amplification and FM assistive listening devices as part of their school and home training programs. Children with stuttering or voice disorders may profit from amplification as they attempt to take the "work" out of voicing, learning to use soft-contact, easy-onset speech patterns.
Many adults with communication disorders may benefit from receiving speech-language pathology services with some amplification of their own speech-voice. The non-fluent aphasic patient, for example, may profit from greater auditory awareness of his own speech with greater emphasis given to the spoken signal. Dysarthric patients and people with voice disorders sometimes seem to produce clearer voice signals as they listen to their own real-time amplified speech.
A trial use of amplification with children and adults with various communication problems can be part of diagnostic evaluations. Does amplification increase accuracy or desirability of response? Responses under amplification can be compared to non-amplified response, using various electronic devices, such as the Visi-Pitch or the Computerized Speech Lab (CSL). If real-time amplification is found to be facilitative, it can then be used in therapy and in self-practice.
Clinicians and teachers using auditory amplification with normal hearing children and adults should be aware of some of the concerns of ASHA’s Committee on Amplification for the Hearing Impaired, as cited in Section 1 of this manual. The settings recommended using the amplification of the Facilitator should not exceed a level that is "comfortable" for the client using the instrument. For clients with normal hearing, this is probably in the 75–85 dB intensity range. As the clinician, you should make volume adjustments with each client so that he/she is comfortable with the amplitude provided (i.e., not too soft or too loud). The benefits from using amplification appear less related to intensity and more to the focus given to the auditory signal that such headphone-directed amplification provides.
Examples of Cases Using Amplification
Danny, age 7, was found to have learning disabilities primarily related to attention span deficits. In his public school classroom, he was found to be easily distracted by competing auditory and visual stimuli. In special out-of-class tutoring sessions, it was found that he could read aloud with second-grade-level accuracy. However, he would only attend to the task of oral reading for about 90 seconds. Wearing headphones and receiving about 75–80 dB of speech level amplification, he would continue to read aloud in excess of five minutes (under amplification, he would often need to be asked to stop the reading task). Further, his oral reading with amplification seemed to increase his voice loudness and his speech would become totally free of articulation errors. Oral reading with real-time amplification of what he says continues to be an important component of his total educational program.
Christeen, a 39-year-old hospital administrator, experienced unilateral left vocal fold paralysis, secondary to a neurosurgical procedure that corrected a ruptured cervical disc by fusing the left cervical 6-7 vertebrae. She was first seen by the SLP some three months after onset of the paralysis. Her whispered "rough" voice was barely audible, sounding typical of a patient with the paralyzed vocal fold in the paramedian position with the normal fold not making much of a midline compensation. As part of our diagnostic procedure, she was asked to continue voicing wearing headphones with real-time amplification of about 80 dB. The effect of amplification on her voice was immediate: Visi-Pitch readings showed an elevation of fundamental frequency, greater loudness, and a marked decrease in jitter ratio. Subsequently, as part of her voice therapy and everyday use of voice, she wore a portable voice amplifier with microphone and headphones. Self-amplification of voice seemed to produce the Lombard effect, creating greater voice loudness (with a concomitant increase in voice quality). Six month post-surgery, innervation of the left recurrent nerve returned and she experienced normal laryngeal function. Voice therapy continued to use amplification as the patient worked to re-establish easy, ongoing prosodic voicing patterns.
Recommended Procedures for Using Amplification
1. The use of amplification in the clinic using the Facilitator, should begin after an explanation to the patient, such as "Let’s see how you sound when you hear yourself speak through these headphones." The clinician then places the headphones on the patient and attaches the lapel microphone, indicating that the patient will now hear both the clinician’s voice and his own on the headphones. Trial loudness levels should be established by adjusting the volume control button.
2. When the Facilitator is turned on, the amplifying mode is on. The instrument may be plugged in and used in the clinic, either on a desk or table or placed inside the wearable carry case and worn as a portable device. The in-clinic usage offers the clinician a separate microphone and headset, enabling direct teaching or modeling with the patient listening on his or her headset. Or the Facilitator can be used strictly as a portable, battery-driven instrument (without the clinician’s headset and mike).
3. Diagnostically, amplification can be used as a specific step in the evaluation of a child or adult with a speech-language-voice-learning problem. It is an add-on procedure that may be coupled with other diagnostic tasks. For example, if a phonetic inventory is administered, amplification could be used during part of the exam. This permits the testing of sounds under both amplified and non-amplified conditions.
4. Use amplification as part of a diagnostic probe. When amplification is added to a diagnostic task, does it make a difference? Different loudness levels should be tried.
5. The use of amplification in therapy and in training sessions is highly individualized. If it has been found to increase correct response rate, improve speech and/or voice, or improve learning through greater focus on auditory stimulation, amplification via headphones should be an important part of therapy. Within the therapy or training sessions, different levels of amplification should be tried, using the lowest levels of amplification that are still facilitative.
6. The portability of the Facilitator makes amplification possible out of the clinic. The child or adult may select to wear the phones with amplification only in self-practice sessions out of the school, clinic, or studio. Some people elect to use the benefits of amplification on their speech-voice by wearing the amplifier with headphones at school, at home, or at work.
7. More often, continuous wearing of the Facilitator in out-of-the-clinic situations is found in those people who elect to use other features of the instrument, such as looping, DAF, masking, or pacing.