Kresge Hearing Research Institute Tour

Dr. John Middlebrooks, Director, Central Systems Laboratory, Kresge Hearing Research Institute leads a guided tour of the Kresge Hearing Research Institute Central Systems Laboratory.

The Central Systems Laboratory conducts research examining the brain mechanisms of hearing, particularly issues related to stimulus coding in the auditory cortex. Some of its current projects center around spatial hearing and auditory prosthesis, including extensive research in cochlear implants. The Laboratory facilities consist of a double-walled anechoic chamber used for human psychophysical studies, a second chamber for animal physiological studies of spatial hearing experiments, and a double-walled chamber used for cochlear implant studies.

John Storyk: Recording Studio Acoustical and Architectural Design


  1. Acoustics of renovated studio
    1. Live room reverb time:0.7 s at 1 kHz with panel doors closed, 0.3 s at 1 kHz with panel doors open
    2. Control room reverb time:0.4 s at 1 kHz
    3. Control has NC of 25
  2. Project turned out well, especially considering challenges:construction crew had never worked on a studio before, and a lot of long-distance communication was needed


  1. John’s first project: Electric Lady Studios (Jimi Hendrix’s studio)
    1. One of the first independent studios, revolutionary for its time
    2. Was personalized in style, very artist-oriented
    3. Control room was much larger than studios of the past
  2. Other projects of John’s – details can be found on John Storyk’s website.
  3. Studio programming should always come before acoustics
  4. If costs need to be cut in studio construction, it’s better to do so in equipment than acoustics
  5. Studios today must have personality to remain competitive, since everyone can own their own personal studio if they so choose
  6. A large factor in studio construction costs is the degree of acoustic isolation desired – more isolation costs more, and the costs have not decreased significantly over time
  7. Acoustic reflections should be controlled, not eliminated – too much absorption is a common acoustical mistake
  8. Ear-level monitoring is ideal and can often be achieved through creative placement of monitors
  9. Symmetric rooms and parallel walls are not necessarily suboptimal acoustically – other factors are more important
  10. Useful acoustic tools:
    1. Plaque diffuser – the best currently-known method for reducing HVAC noise
    2. Helmholz resonator – low-frequency absorber, high-frequency diffuser
    3. Membrane absorbers
    4. Perforated wood paneling

Digital Signal Processing: Daniela Marquez

Daniela will give an overview of audio signal processing on the SigmaDSP IC chip from Analog Devices. The talk will focus on effects processing and how the IC is programmed. Demonstrations will be included in this discussion.

Daniela Marquez graduated from the University of Michigan in 2006 with a double major in Electrical Engineering and Sound Engineering (PAT-D). Currently she works at Analog Devices Inc. as a Software Systems Engineer in the Digital Audio Group. Daniela has been working on algorithm development for the audio processing IC: SigmaDSP. Her current projects include Automatic Room Equalization and Effects Processing.