Altered Auditory Feedback

Some Perspectives..

What is Altered Auditory Feedback (AAF)?

A definition:

“AAF is a collective term for conditions that involve electronically altering the speech signal so speakers perceive their voice differently from normal” (Lincoln, Packman and Onslow 2006)

Types of AAF

Masking

• Edinburgh masker 1970s

• Interest waned in the 1980s : problems with continuous usage, and discovery that DAF and FAF were more effective

Types of AAF

Delayed Auditory Feedback : DAF• Delay of conductive voice signal by typically 50-

100 ms. Speakers experience this as a delay in hearing what they have just said.

• Historically used as a method for inducing prolonged speech (Goldiamond 1965)

• Only in the 1990s was DAF alone considered as a treatment for stuttered speech.

Types of AAF

Frequency Altered Feedback : FAF

• Shifting the frequency of the speakers voice up or down, typically between a ¼ to 1 octave. Speakers hear their voice at a higher or lower pitch than usual.

General effects of Altered Auditory Feedback (DAF and FAF)

• DAF and FAF both shown to reduce stuttering in reading tasks in lab conditions by 40-85%

• An estimated 10% show no reduction under these conditions

• Children ( 9-11) showed a smaller reduction than adults under these conditions (10%as opposed to 65% reduction). Howell et al 1999

General effects continued..

• Reduced speech rate is not essential for stuttering reduction to occur under AAF conditions (though a smaller reduction occurred in faster speech rates)

• Listeners rated enhanced speech naturalness as opposed to no AAF (Stuart and Kalinowski 2004)

Conditions under which AAF has been researched

• Manipulation of delay: 50 ms best for most (Kalinowski et al 1996). But individual differences

• Manipulation of Frequency shift: ¼ octave may be best for most (Stuart et al 1996). But individual differences

• Monaural v binaural delivery. Binaural may be more effective (Kalinowski and Rastatter 1997).Left v right ear, no significant differences

Speaking Tasks

• Oral reading and monologue have been extensively researched. Oral reading has the best results

• Conversation- as yet no real experimental evidence about day today use outside the clinic.

• Telephone ( scripted calls, from a clinic), though authors say there was spontaneous conversation too. Significant reduction in stuttering( Zimmerman et al 1997)

Speaking tasks..

• Audience size (reading aloud). Argued audience size will provoke anxiety. Approx 75% reduction in stuttering regardless of audience size (2,4,15 people). Armson et al 1997

AAF as a treatment

Very little reported to date

Van Borsel et al (2003)

• Looked at DAF (Casa Futura School DAF)

• Sampled speech before and after 3 months of daily use

• Assessed on reading, picture description and conversation (in the clinic only)

Findings..

• At initial assessment immediate reduction in stuttering noted across all speech tasks

• More stuttering noted in conversation as compared to oral reading and picture description

• The reduction noted on first assessment was maintained after 3 months, with, again, conversation showing less reduction in stuttering

• Some carry over effects of DAF noted as NAF tasks were significantly more stutter free after 3 months

• No speech naturalness data reported

Stuart et al (2004)

• Used SpeechEasy device (FAF and DAF) with 4 adults and four youths

• 4 month follow up period• Significant reduction in stuttering in both

assessments (within clinic)• No carry over effects noted• Speech naturalness judged higher using

the device (except in the youths in monologue tasks)

What is successful treatment?

Is it reduction in %SS, such as these studies have been examining?

OR…

are there other parameters we should be looking at?

• E.g. reduction in avoidance• E.g. reduction in struggle• E.g. being more open about stuttering• E.g. enjoying more speech related challenges

• Heidi takes over here…

Some final comments..

• We need good assessment procedures • We need to know more about using the device

outside of clinic conditions: in particular conversational speech, telephone use etc

• We need to think about where we stand as regards children using these devices

• We need to think about whether AAF should be used with other treatment strategies e.g. prolonged speech

But most importantly we need to know what our clients think of the devices and

…what they are wanting from treatment

Referencesin order of presentation

Lincoln M., Packman A., Onslow M. (2006) Altered auditory feedback and the treatment of stuttering: a review. Journal of Fluency Disorders 3 , 71-89Goldiamond, I. (1965). Stuttering and fluency as manipulatable operant response classes. In L. Krasner & L. Ullman(Eds.), Research in behaviour modification. New York: Holt, Rinehart and Winston.Howell, P., Sackin, S., & Williams, R. (1999). Differential effects of frequency-shifted feedback between child and adultstutterers. Journal of Fluency Disorders, 24, 127–136.Stuart, A.,&Kalinowski, J. (2004). The perception of speech naturalness of post-therapeutic and altered auditory feedbackspeech of adults with mild and severe stuttering. Folia Phoniatrica et Logopaedica, 56, 347–357.

ReferencesKalinowski, J., Stuart, A., Sark, S., & Armson, J. (1996). Stuttering

amelioration at various auditory feedback delays andspeech rates. European Journal of Disorders of Communication, 31,

259–269.Stuart, A., Kalinowski, J., Armson, J., Stenstrom, R., & Jones, K.

(1996). Fluency effect of frequency alterations ofplus/minus one-half and one-quarter octave shifts in auditory feedback

of people who stutter. Journal of Speech andHearing Research, 39, 396–401.Stuart, A., Kalinowski, J.,& Rastatter,M. P. (1997). Effect of monaural

and binaural altered auditory feedback on stutteringZimmerman, S., Kalinowski, J., Stuart, A., & Rastatter, M. (1997). Effect

of altered auditory feedback on people whostutter during scripted telephone conversations. Journal of Speech,

Language and Hearing Research, 40, 1130–1134.

ReferencesArmson, J., Foote, S., Witt, C., Kalinowski, J., & Stuart, A. (1997).

Effect of frequency altered feedback and audiencesize on stuttering. European Journal of Disorders of Communication,

32, 359–366.Van Borsel, J., Reunes, G., & Van den Bergh, N. (2003). Delayed

auditory feedback in the treatment of stuttering: Clientsas consumers. International Journal of Language and Communication

Disorders, 38, 119–129.Stuart, A., Kalinowski, J., Rastatter, M., Saltuklaroglu, T., & Dayalu, V.

(2004). Investigations of the impact of alteredauditory feedback in-the-ear devices on the speech of people who

stutter: Initial fitting and 4-month follow-up.International Journal of Language and Communication Disorders, 39,

93–119