Examples using fully online / browser-based platforms

Using Amazon Mechanical Turk for a ‘One Shot’ Study: Famous speaker recognition

Questions of Interest:

Examining whether voice recognition relies on fundamental frequency (absolute pitch).

Platform / Infrastructure:

Amazon Mechanical Turk. Sounds were hosted on a university server.

Participant Recruiting:

Limited recruitment to participants in the USA and Canada.


Participants are consented and then fill out a short demographic survey. Before they are able to complete the experiment they must pass a brief screening to ensure that they are wearing headphones (described in Headphone screening to facilitate web-based auditory experiments. K J P Woods, M Siegel, J Traer and J H McDermott. Attention Perception and Psychophysics, vol.79 pp. 2064-2072, Jul 2017). This screening helps standardize online sound presentation.

In the main experiment, participants heard voices that were pitch shifted up or down up in increments ranging between -12 semitones to +12 semitones. They were asked to identify the speaker they heard. Speakers included well-known actors/actresses, politicians, newscasters, etc. Participants freely typed in their responses, and responses were blindly coded post-hoc. They could enter information about a movie/character played by the person, what TV show they hosted, etc. Because answers were free-response, we did not have performance monitoring, and paid all participants the same flat fee.

Conclusions / Impressions:

Online recruitment allows us to examine phenomena where there are a limited number of times and/or items with which we can query participants. In this case, there are a limited number of voices that participants may know, and once we have queried a participant with a particular voice, we cannot ask them about that voice again. Each participant in these studies only heard each voice once (‘One Shot’), and pitch shifts were randomized across participants. This solution is not practical in a laboratory setting (this study took less than 10 minutes, but required >200 participants). We have done similar ‘One Shot’ procedures examining melody recognition, pitch discrimination, and auditory attention.


Malinda J. McPherson, mjmcp@mit.edu

Additional information and study description: Diversity in pitch perception revealed by task dependence M J McPherson and J H McDermott. Nature Human Behavior, vol.2 pp. 52-66, Jan 2018