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Correlation Study and Control of Mechanical Vibration

A detailed technical understanding and control of psychoacoustics and mechanical vibration are essential to developing psychoacoustic control strategies on hard disk drive.

Project leader

Dr Cheng Siong Chin

Dates

April 2013 - March 2018

Project staff

Professor Ehsan Mesbahi

Sponsors

Singapore Economic Development Board (EDB)

Seagate Technology Singapore Science Park R&D Center

Partners

Seagate Technology Singapore Science Park R&D Center

Description

In the hard drive industry, hard disk drive acoustics are becoming important.

With the introduction of hard drives into new emerging markets the consumer is more aware of and sensitive to radiated acoustic noise issues caused by vibration. Engineers are facing great challenges to meet customer demands.

Drive manufacturers are under severe cost constraints, many times unable to incorporate all the noise control devices necessary to make drives quieter.  

It is well understood that the mechanical noises come from vibrations. But is not a purely mechanical phenomenon of wave propagation. It is also a sensory and perceptual event called 'psychoacoustic'.

When a person hears a sound, it arrives at the ear as a mechanical sound wave travelling through the air. Inside the ear it transforms into neural action potentials. The brain senses these never pulses.

In HDD field, there are three psychoacoustic parameters:

  • Loudness 
  • Sharpness
  • Pure Tone

We measure these parameters with high sensitivity microphones. It is done in an environment with the lowest background noise.

We measure the mechanical vibration by attaching an accelerometer on the HDD casing under most of environment.

A detailed technical understanding and control of psychoacoustics and mechanical vibration are essential to developing psychoacoustic control strategies on hard disk drive.