Mass project

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Welcome to the Masking Ambient Speech Sounds project Wiki. The project is on-track to begin listening trials on the 21st of July.

Experiments

Experiment 1

The first listening tests will involve project staff members to check if things make sense. If it looks good we'll start working with non-project volunteers. Experiment 1, in the the CCRMA "Pit," will take about 30 mins. and involve 30 trials. There will be 6 conditions of masking sound crossed with 5 conditions of speech sounds. The masker (FM noise) and the speech sounds will be presented as if the sources are outside the room. We'll use the measured room model from Tokyo and the exterior sound source position (hallway). The "as if" impression will be created by convolving with the measured impulse responses.

Necessary ingredients: (x = done)

  1. (x) ambient room sound recording from Tokyo
  2. (x) 15 sec. recordings of FM noise masker with parameter variation
  3. (x) 4 min. recordings of 4 conversations (animated / not-animated, crowd / pair, always 50% gender balance)
  4. 15 sec. clips cut from conversations
  5. (x) convolved versions of 15 sec. files putting them "as if" in the hallway
  6. GUI for running randomized listening, A/B forced choice, logging results

--Cc 15:10, 17 July 2006 (PDT)

Strategies to define conditions of FM masing noise

To define the conditions of this first experiment, the approach will be to leave all the parameters fixed, except the modulation frequency.

Noise set Contains a complete technical documentation of the masking noise generation. Is also contains the soundfiles.

The conditions of the masking FM noise will be defined by the following criteria:

  • 3 bands of FM noise will be used (centered at 200 350 and 500 Hz):
    This bands are selected based on an anaylis of speech voice recorded in the Tokyo office. The motivation between this decision is to identify the relevant parameters in the leaking voice. For example, we know that the wall is filtering much of the high frequency components, so that's relevant in the selections of tha main frequencies.
  • The amplitude (volume) of each band will be fixed:
    The amplitud was tuned in orded to psicoacoustically balance the level of the three noise bands that will be used. This balance was done without modulation.
  • The amplitude of the modulation will be proporstional to the modulation frequency:
    The motivation behind this choice is to minimize the anoyance effect. When the modulation rate is low, higher amplitudes are more noticed and anoying.
  • The relation between of modulation frequency of the 3 bands is then the main factor to define the conditions:
    For this experiment, 3 modulation rates are selected, 2, 5 and 7 Hz. The idea is to span some of the frequencies in the range of 2 to 7 Hz. Basically, all the combination of these 3 rates are used for each center frequency, plus a case with no modulation at all.


This experiment will be then testing the masking efficency and annoyance bance on the realtion of the modulation frequencies of the bands.
--Jcaceres 14:10, 20 July 2006 (PDT)

Conference Call Meetings

July 18, 2006

  • FM Modulation discussion (Yasushi's Comments, with Juan-Pablo's comment on answer A:):
  1. Do you have any idea how to specify frequency modulation for each frequency band?
    • A: based on speech freq, ~2-8 Hz
  2. The period in time for each frequency should be the same?
    • A: No, different. When it's the same the masking efficiency decreases. It seems also more anoying.
  3. Modulation speed will be getting faster according to higher frequency, or
    • A: I don't know yet, this is going to be the main parameter in the first experiment I think.
  4. The frequency modulation considering the voice sound
  5. We have to analyze how the voice sound is modulated in different frequency bands?
    • A: I thiks this is the best way, and we have to consider that the wall is filtering almost all the high frequencies.
  • Discussion of the experiment setup.
  • Look at the documentation, the new example of impulse responses, and delay of arrival.

--Jcaceres 17:44, 18 July 2006 (PDT)

July 24, 2006

Monday 5:30PM Stanford
Tuesday 9:30AM Japan


Links

--Jcaceres 17:33, 17 July 2006 (PDT)