Nonacoustic

For reducing tonal noise, e.g., generated by engines and propellers, the reference microphone can be replaced by a nonacoustic reference sensor, e.g., a tachometer or an optical or inductive sensor.

In addition, the score features common acoustic and nonacoustic Western instruments, including keyboards, synthesized drums and bass, electric and acoustic guitar, piano, and accordion.

Compared with vestibular schwannomas, eighth cranial nerve symptoms and signs are less frequent, and other cranial nerve and cerebellar symptoms and signs are more frequent in nonacoustic CPA tumours.