The Potential Effect of Forbrain as an Altered Auditory Feedback Device

Abstract

The results of this study indicate the effectiveness of Forbrain® in modifying the speech of its users. It is suggested that Forbrain® works as an altered auditory feedback device. It may hence be used as a clinical device in speech therapy clinics, yet further studies are warranted to test its usefulness in clinical groups.

The potential use of Forbrain® in stuttering: A single-case study

“…For LTAS, (5) the general spectral slope (sLTAS) was measured as the difference between the energy in the 0 ---1 kHz range and the energy in the 1---10 kHz range of the long-term average spectrum; and (6) the spectral trendline inclination (tilt; tLTAS) was computed as the difference between the energy in the 0 ---1 kHz range and the energy in the 1---10 kHz range of the trendline through the long-term average spectrum. Based on our previous study on healthy volunteers (Escera et al, 2018), we expect that the most sensitive and clinically relevant parameters would be CPPS and tLTAS.…”

“…This pattern of results, with effects observed solely on two of the six measurements and consisting on a effective change taking place during the phase in which the device was turned on, can be considered specific and transient. Specific because effects occur on two voice parameters formerly observed to be affected by Forbrain ® in a sample of healthy volunteers with no personal nor family history of speech and language disorders (Escera et al, 2018); transient because they were circumscribed to the time moments in which the device was active. This is clinically very relevant, as it supports using Forbrain ® as a device, one providing a form of AAF, that can have a direct impact in the speech performance of it stuttering users.…”

“…Voice was chosen as dependent variable because it allows objective and quantitative analysis based on its sound recording, beyond subjective interpretation. Besides, a recent study supported the use of voice to investigate Forbrain ® effects, particularly on two specific objective measures: smoothed cepstral peak prominence (CPPS) and spectral trendline inclination (tilt; tLTAS) (see below; Escera et al, 2018).…”

“…The resulting sound is delivered through the bones by a process of bone conduction, so that the travelling waveform of a sound can reach the inner ear, induce a travelling wave in the basilar membrane and hence stimulate the cochlea by the same mechanisms as normal air conduction but via bone vibration (Stenfelt & Goode, 2005). Compared to other AAF devices for the treatment of stuttering, one major difference of Forbrain ® is that it provides AAF in the amplitude domain (Escera, López-Caballero, & Gorina-Careta, 2018), similar to that of the semitone amplification (Bauer et al, 2006;Garber et al, 1976;Heinks-Maldonado & Houde, 2005) or feedback filtering (Burzynski & Starr, 1985;Garber et al, 1976Garber et al, , 1980Garber et al, , 1981. Moreover, a recent study conducted in healthy volunteers with no personal or familiar history of speech or language disorders showed that Forbrain ® , when in use, alters the speaking voice of its users (Escera et al, 2018).…”

“…Compared to other AAF devices for the treatment of stuttering, one major difference of Forbrain ® is that it provides AAF in the amplitude domain (Escera, López-Caballero, & Gorina-Careta, 2018), similar to that of the semitone amplification (Bauer et al, 2006;Garber et al, 1976;Heinks-Maldonado & Houde, 2005) or feedback filtering (Burzynski & Starr, 1985;Garber et al, 1976Garber et al, , 1980Garber et al, , 1981. Moreover, a recent study conducted in healthy volunteers with no personal or familiar history of speech or language disorders showed that Forbrain ® , when in use, alters the speaking voice of its users (Escera et al, 2018). The present report describes a single-case time-series study, implemented with an A-B-A design, on an adult who stutters, on the potential effects of Forbrain ® on the user's voice.…”