four sound track stereo radio

multiple sound track

Optical Sound Track

photographic sound track

sound track printer

sound-track engraving apparatus

two sound track stereo radio

going on the track of sound progress

engineering district；maintenance of way section；track division；track district；track maintenance division

a sound mind in a sound body

infra-audible sound (=infrasonic sound)

rate of sound and attenuation of sound

sound absorption-sound insulation-vibration isolation technology

sound intensity and sound intensity level

sound navigation and ranging or sound radar

sound pressure and pressure level of sound

sound-on-sound

jointless line；continuously welded rail track；jointless track

non-NTDS track {dummy track}