Providing innovative Product Sound Quality Evaluation Methods (Noise & Vibration Control Engineering) including the Percentile Frequency method for impulsive sounds and the Music Analogy strategy for sound quality engineering
Percentile Frequency Method for Evaluating Impulsive Sounds
The Percentile Frequency Method evaluates the relative frequency content of impulsive or impact sounds based on calculations using waterfall data of Zwicker Specific Loudness Patterns. For details on the Percentile Frequency Method see:
Paper No.1999-01-1851, Percentile Frequency Method for Evaluating Impulsive Sounds by R.J. Fridrich from the Proceedings of the 1999 Noise and Vibration Conference, Society of Automotive Engineers.
Paper in02_153, Percentile Frequency Method and Zwicker Loudness by R.J. Fridrich from the Proceedings of the 2002 International Congress on Noise Control Engineering (Inter-Noise 2002). This Conference was sponsored by the Institute of Noise Control Engineering-USA (www.INCEUSA.org) The appendix of the Inter-Noise paper contains MS-Excel macro-code listing for performing the calculations.
Copy and paste the listing of the MS-Excel macro code from the %-ile Freq Macro tab or download as a PDF file by clicking on the link. Cband8 and Cband10 are macro codes for converting display line numbers into frequency values for data from B&K and HEAD acoustics systems respectively.
Relative Pitch Evaluation of Tones
Relative Pitch Evaluation of Tones uses the pitch intervals associated with the equal-tempered musical scale to evaluate time-variations in tones that are produced by products that use electric motors. For details on the Relative Pitch Evaluation of Tones see:
Paper No. 2003-01-1503, Pitch Intervals: Linking Sound Quality Engineering and Musical Acoustics by R.J. Fridrich from the Proceedings of the 2003 Noise and Vibration Conference, Society of Automotive Engineers.
Pitch Matching for Impulsive Sounds
Pitch Matching for Impulsive Sounds is a subjective technique that matches the indefinite pitch of the test impulsive or impact sound to a user-controlled reference sine burst (a portion of a sine wave of a given frequency and fixed number of periods). For details on the Pitch Matching method see:
Paper No. 971981, Pitch Matching for Impulsive Sounds by R.J. Fridrich from the Proceedings of the 1997 Noise and Vibration Conference, Society of Automotive Engineers.
Pitch Measurement of Door Closing “Thump”
A preliminary investigation was made of Gardner and Magnasco’s Instantaneous Frequency Decomposition method (IFD) as a way to measure the fundamental pitch of door closing sounds (“Thump”). The results were encouraging but further study is needed. For details see:
Paper No. 2007-01-2216 Measuring the Pitch of Door Closing Sounds - The Sound Quality Issue of Door “Thump” by R.J. Fridrich from the Proceedings of the 2007 Noise and Vibration Conference, Society of Automotive Engineers.
Reflections were detected in an anechoic room that was constructed using Perforated Metal Wedges. These reflections can have adverse effects on the results of Impulsive Sound Quality Tests. The development of a new standard for qualifying anechoic rooms is recommended. For details see:
Paper No. 2007-01-2217 Is This Room Anechoic? A New Anechoic Room Qualification Standard May Be Needed for Impulsive Sound Quality Tests by R.J. Fridrich from the Proceedings of the 2007 Noise and Vibration Conference, Society of Automotive Engineers.
Music Analogy for Product Sound Quality
The Music Analogy is offered as a guide to developing Product Sound Quality requirements using ideas from Music Notation and Music History. This approach is suggested as an alternative to widely used methods that rely on statistics and correlation. For details on the Music Analogy see:
Paper No. 2005-01-2477 Music Analogy: An Alternative Strategy for Sound Quality Requirements by R.J. Fridrich from Proceedings of the 2005 Noise and Vibration Conference, Society of Automotive Engineers.
