Hd 448

Participants for the rating experiment were recruited in the Cafeteria of the Georg-August-University of Göttingen and at the German Primate Center, Göttingen, Germany. They were all native German speakers. Two-hundred and twenty-eight subjects participated (69 female and 59 male) in the rating experiment. The subjects were students (N = 99) or scientific assistants (N = 29). Every single stimulus was thus rated by 32 subjects. Eighty of the subjects were between 18 and 24 years of age, 36 between 25 and 29 years, seven between 30 and 34 years and five subjects 35 years or older.
The stimuli were played back with a laptop (Toshiba Satellite M70-187 with a Realtek AC97 Soundcard) via NBS Presentation. Subjects heard the stimuli via earphones (Sennheiser HD 448 and HD 280 pro). Before the experiment started, subjects read a description about their task and the experimental procedure. All remaining questions were answered before the experiment started, after which there was no further interaction between participant and experimenter and the trials were played back automatically by Presentation as defined in the script.

Participants sat in an acoustically isolated chamber in front of video monitor where they read instructions for the experiment. They wore Sennheiser’s HD 448 headphones. On a given trial, they were presented with one of the four possible targets superimposed with additive white noise. The SNR was adapted from one trial to the next based on the performance level using a 3-down 1-up staircase procedure to target the 79% correct point [50 ]. All stimuli were power-normalized and presented at each participant’s most comfortable sound level.
The task of the participant was to identify the last syllable of the stimulus as /da/ or /ga/, independently of the preceding consonantal context, and to respond as quickly as possible by a button press. The response to trial i is denoted r_i (0 for ‘da’ and 1 for ‘ga’). Participants were allowed to play the stimulus as many times as needed, however they nearly always respond after the first listening. The experiment was divided into 20 sessions of 500 trials each, separated with breaks and completed over 4 days. The total length of the experiment (10,000 stimuli plus cognitive and phonological tests) was approximately 4 hours. Data from all participants are available at https://zenodo.org/record/12303 and https://zenodo.org/record/19129.