Auditory Masking Effects on Speech Fluency in Aphasia and Apraxia of Speech

Completed

Phase N/A Results N/A

Trial Description

Impaired speech production is a major obstacle to full participation in life roles by stroke survivors with aphasia and apraxia of speech. The proposed study will demonstrate the short-term effects of auditory masking on speech disfluencies and identify individual factors that predict a positive response, enabling future work to develop auditory masking as a treatment adjuvant targeting long-term improvement in speech. Providing an additional treatment option for adults with aphasia and apraxia of speech will have the clear benefit of improving quality of life and allowing individuals to participate more actively in their health care decisions through improved communication.

Detailed Description

The objective of this research is to test the short-term effects of listening to noise (i.e. auditory feedback masking) on speech fluency in stroke survivors with aphasia and apraxia of speech. People with nonfluent types of aphasia frequently have apraxia of speech, which affects the motor programming of speech movements, causing distortions, slow rate, and speech disfluencies that impede the forward flow of communication. Speaking while listening to noise (e.g. auditory masking) is known to reduce disfluencies and increase speech rate in people who stutter. This method has been tested in people with aphasia, resulting in positive effects on speech production for a subset of those tested. The investigators contend that individuals who have apraxia of speech in addition to aphasia are most likely to benefit from auditory masking, but most previous studies did not test participants for apraxia of speech. In addition, though masking is most likely to affect speech disfluencies, previous studies did not measures disfluencies. The proposed work has two specific aims. Aim 1 will determine the short-term effect of auditory masking, provided on a single day, on speech fluency in stroke survivors with aphasia and apraxia of speech. Aim 2 will identify individual factors that predict a positive response, including presence of apraxia of speech, lesion characteristics, and type of aphasia (e.g. Broca's, Wernicke's). Voxel-based lesion analysis techniques will be used to determine sites of lesion associated with positive and negative response to auditory masking. Completion of this study will remove barriers to studying auditory masking as a technique for clinical intervention, but also as a research tool for behavioral neuroscientists probing the speech motor control system in speakers with aphasia and apraxia of speech.

Conditions

Interventions

  • Normal Auditory Feedback Behavioral
    Intervention Desc: Participants will produce sentences under normal speaking conditions, able to hear their own speech.
    ARM 1: Kind: Experimental
    Label: Aphasic/Apraxic Participants
    Description: The aphasic/apraxic participant group will include 30 adults who have had strokes affecting their ability to communicate verbally, broadly classified as aphasic and including individuals with and without apraxia of speech (AOS). Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.
    ARM 2: Kind: Experimental
    Label: Neurologically Healthy Participants
    Description: The neurologically healthy participant group will include 15 adults with no history of stroke or developmental speech or language disorder. Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.
  • Masked Auditory Feedback Behavioral
    Other Names: Masking Noise
    Intervention Desc: Participants will produce sentences while listening to speech-shaped noise at 85 decibels (sound pressure level) to mask ability to hear their own speech.
    ARM 1: Kind: Experimental
    Label: Aphasic/Apraxic Participants
    Description: The aphasic/apraxic participant group will include 30 adults who have had strokes affecting their ability to communicate verbally, broadly classified as aphasic and including individuals with and without apraxia of speech (AOS). Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.
    ARM 2: Kind: Experimental
    Label: Neurologically Healthy Participants
    Description: The neurologically healthy participant group will include 15 adults with no history of stroke or developmental speech or language disorder. Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.
  • Altered Auditory Feedback Behavioral
    Other Names: Delayed and pitch-shifted feedback
    Intervention Desc: Participants will produce sentences while listening to their speech shifted up one octave and delayed.
    ARM 1: Kind: Experimental
    Label: Aphasic/Apraxic Participants
    Description: The aphasic/apraxic participant group will include 30 adults who have had strokes affecting their ability to communicate verbally, broadly classified as aphasic and including individuals with and without apraxia of speech (AOS). Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.
    ARM 2: Kind: Experimental
    Label: Neurologically Healthy Participants
    Description: The neurologically healthy participant group will include 15 adults with no history of stroke or developmental speech or language disorder. Participants will speak under Masked Auditory Feedback, Altered Auditory Feedback, and Normal Auditory Feedback.

Trial Design

  • Observation: Case Control
  • Perspective: Cross-Sectional
  • Sampling: Non-Probability Sample

Trial Population

Participants with aphasia (PWA) will be referred from existing referral sources (e.g. UNC Stroke registry, Triangle Aphasia Project), clinicians in the community, and the Carolina Data Warehouse for Health.

Outcomes

Type Measure Time Frame Safety Issue
Primary Disfluency duration change with masking noise 1 day of the study No
Secondary Speech rate change with masking noise 1 day of the study No
Secondary Speech sound accuracy change with masking noise 1 day of the study No

Sponsors