دانلود رایگان مقاله ارزیابی سایکوآکوستیک از سیگنال های شنوایی در خودروهای سواری

Abstract

Twenty-one experienced drivers were recruited for the evaluation of sounds of four functions (horn, indicator, door open warning, and parking sensor) made by 11 car brand names. Each participant was required to evaluate all of the above sound signals by a pair-comparison test. After the comparison test, each participant was shown his/her pair-comparison result and was asked to comment on their preference and appropriateness of a sound. The physical properties and interview data were compared and summarized to propose design recommendations. Our results indicate that complex tones and a fundamental frequency between 500 and 1000 Hz were most preferred for horns while for indicators the preferred sounds had a higher dominant frequency. To reduce monotony, the indicators with double clicks and an OFF time interval of between 330 and 400 ms between two clicks were most preferred. Regarding door warning sounds, the waveform starting with a higher intensity then fading towards zero intensity is most preferred while for parking sensors, sounds beginning with a longer OFF time (about 500 ms) and having 3 or 4 distinctive tempo variations were most preferred. The relationship between pleasurability and pitch, loudness, and the tempo of sound signals basically followed an inverted-U function. Sound designers should avoid using very extreme parameter values when generating sound for a given function.

5. Conclusion

New in-car technologies have led to an increasing number of sound signals (Suied et al., 2008). In order to reduce the confusability of a warning set, the number of immediate-action warning sounds should not exceed about five to six, each with a distinctive melody and temporal pattern (Patterson and Mayfield, 1990). The current study tested sound signals for horns, indicators, door open warnings, and parking sensors, from 11 car brands, using a paired-comparison test and an interview to gain more insight into human preference of sounds. By comparing analyses from our paired-comparison results, interview data, important sound attributes, and our literature review of existing standards, we propose an optimal range for important acoustic parameters. Sound designers can produce sounds within a feasible range, based on available standards. Then, they can choose a dominant fundamental frequency between 500 and 2000 Hz and adjust based on best practices; e.g., a lower fundamental frequency range for horns (between 440 and 480 Hz) and a higher dominant frequency for indicators (up to 2400 Hz). Since the relationship between pleasurability of tones and a given parameter basically followed an inverted-U function, sound designers should avoid using very extreme parameter values. Lastly, warnings should be readily distinguishable among themselves in terms of temporal pattern (Patterson, 1982), ON/OFF ratio, and attenuation pattern (Meredith and Edworthy, 1994) to reduce monotony and further improve the perceived quality.