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Speech Acoustics and Perception Lab


Speech Acoustics and Perception Lab

The Speech Acoustics & Perception Lab studies the different factors that affect how people understand speech, including the characteristics of the speaker, the listener, and the environment.

About the Lab

The Speech Acoustics & Perception Laboratory examines talker, listener, and environmental factors associated with successful speech understanding as well as communication breakdowns. Projects range from perceptual experiments where listeners identify or rate what they've heard, to acoustic analyses of previously-recorded speech materials, to speech production studies where participants' speech is recorded across various tasks and test conditions. Our results provide important information to audiologists, speech-language pathologists, and other speech and hearing professionals about how listener hearing status, talker characteristics and behaviors, and environmental conditions all play a part in how we understand speech.

Our Methods

For most studies, listeners are tested in a 7'x7' sound-treated room in front of a computer monitor, keyboard, and mouse. The booth has a large window overlooking the Salt Lake Valley. Other studies are carried out in a larger IAC audiometric test booth located elsewhere on the 12th floor.

In a typical perceptual study, test sounds are presented at conversational listening levels via insert earphones using a Tuck-Davis Technologies Psychoacoustics and Speech workstation and computer located outside the test room. Listeners usually respond to stimuli by clicking on categories shown on the monitor, such as by choosing the vowel they heard or rating how clearly a sentence had been spoken.

Speech production studies may involve reading works, sentences, or passages aloud from a computer screen or printed list or more spontaneous tasks like describing pictures. Speech is recorded using a headset microphone, other equipment may also be used to record respiration or voicing.

Current Studies

     Many communication partners of people with hearing loss say that when they speak clearly, their partner thinks they're mad at them.  A series of studies from the SAP lab have confirmed that, on average, clear speech is indeed rated as sounding angry more often than conversational speech. But what is causing this increase in perceived anger? This question is being investigated from several angles by various lab members, including acoustic analyses and perceptual studies that modify acoustic elements of clear speech to examine changes in perceived emotion.

    Patients receiving support from a mechanical ventilator have traditionally required invasive ventilation, with a tube inserted directly into the airway. An alternative is non-invasive ventilation (NIV), which replaces the invasive tube with a face mask. While the use of NIV is expanding in many settings, a drawback as it severely hinders patients’ ability to communicate effectively. The SAP laboratory is currently collaborating with Axon Medical and the University of Utah Anesthesiology department to test a microphone system that enhances communication in patients undergoing NIV. Testing with young healthy volunteers as well as with patients in the ICU produced promising results, with intelligibility and comprehensibility increasing significantly while using the NIV microphone device. 

    Lab Members


    Graduate Assistants

    Liz Young


    Isabella McHugh


    Tara Smalley


    Sierra Bennion


    Kayleena Faulkner


    Available Speech Materials

    The Ferguson Clear Speech Database

    The Ferguson Clear Speech Database was developed at Indiana University in 2002. It consists of high-quality recordings of 41 talkers reading 188 sentences aloud twice: under instructions to speak as though they were having a normal conversation (conversational speech) and under instructions to speak as though they were talking to a person with hearing loss (clear speech).

    Of the 188 sentences, 174 were created by inserting keywords into neutral sentence frames. Keywords were either vowels in /bVd/ context (7 tokens per vowel, each in a different frame) or monosyllabic words from the NU-6 (a separate list in each style, two tokens per word, each in a different frame). The remaining sentences, 14 per speaking style, were selected from the CID Everyday Sentence test.

    Use of the Ferguson database is FREE for noncommercial use. Contact Dr. Sarah Hargus Ferguson for information about how to access materials.

    **All presentations and publications of research carried out using materials from the Ferguson Database must include the following acknowledgment: Development of the Ferguson Clear Speech Database was support by NIH grant DC02229 to Diane Kewley-Port.

    The Utah Speaking Style Corpus

    The Utah Speaking Style Corpus consists of recordings of conversational and clear speech from several speech production studies carried out in the past 10 years. Contact Dr. Sarah Hargus Ferguson for more information.

      • Young, E.D., Ellerston, J.K., & Ferguson, S.H. (2022, May) The relationship between perceived speech clarity and dysphonia: Preliminary investigation. 182nd Meeting of the Acoustical Society of America, Denver, CO.
      • *Young, E.D., Brewer, L.M., & Ferguson, S.H. (2021, March) Feasibility testing of a microphone system to facilitate patient communication during noninvasive ventilation: Preliminary results. Utah Speech-Language Hearing Association 2021 Conference Virtual Conference
      • *Young, E., Ferguson, S. (2020, December). Talker differences in clear and conversational speech: Perceived emotional valence. 179th Meeting of the Acoustical Society of America, Virtual Conference.
      • Hunter, E., & Ferguson, S.H. (2018, November) The aging voice: Perceived age & voice quality. American Speech-Language-Hearing Association Convention, Boston MA

    Contact Us 

    Phone: 801-585-0036

    Speech Acoustics and Perception Laboratory

    390 South 1530 East, Room 1218
    Salt Lake City, UT 84112


    Behavior Health Science Building