From Wiktionary, the free dictionary
dezi- (“deci-”) + Bel (“bel”)
Dezibel n (strong, genitive Dezibels, plural Dezibel)
- decibel (a common measure of sound intensity)
Declension of Dezibel [neuter, strong]
- “Dezibel” in Duden online
- “Dezibel” in Digitales Wörterbuch der deutschen Sprache