Identifying causes of noise in hard disk drives

In addition to ensuring capacity, access times, reliability and form factor, optimizing acoustic properties – or, in other words, eliminating perceptible interfering noises – is a primary objective when developing hard disk drives. Individual frequencies emanating from the hard disk drive’s electromagnetic circuit are a major source of noise.

Whistling noises in electric motors are caused by individual components being stimulated to produce vibrations during operation. Scanning vibrometry helps to systematically measure the drive’s and its components’ operational vibrations in terms of frequency, amplitude and deflection shape. The results allow the user to correlate the causes of the major interfering sounds very well with the vibration behaviour of a hard disk motor’s individual components. To reduce unwanted noises, you can then use the measurement results both to purposefully optimize the components’ proportions and their relative position to one another and to suppress the interfering sounds to below a specific perception threshold.