Convert Centibels to Decibels

Convert Centibels (cB) to Decibels (dB) instantly and accurately.

Conversion Formula

dB = cB × 0.1

About Centibels

The centibel (cB) is one-hundredth of a bel (1 cB = 0.01 B = 0.1 dB), equal to exactly one-tenth of a decibel. This resolution is the standard for clinical audiometry and professional audio equipment. The pure-tone audiogram (ISO 8253-1, ANSI S3.21) records hearing thresholds at 5 dB (50 cB) steps for screening, but research audiometers adjust in 0.25 dB (2.5 cB) steps for precise threshold measurement. The human just-noticeable difference (JND) for loudness of a 1 kHz tone at 70 dB SPL is ≈ 1–3 cB (Moore, 2012), rising to 5–10 cB near the absolute hearing threshold. IEC 60268-5 specifications for loudspeakers require frequency response plots with centibel (0.1 dB) resolution. In studio monitor calibration (SMPTE RP 200, ITU-R BS.1116), loudspeaker level matching is verified to within 0.1 dB (1 cB). 1 cB = 0.01 B = 0.1 dB ≈ 0.011513 Np.

About Decibels

The decibel (dB) is the universal unit of sound level and signal level in acoustics, audio engineering, and telecommunications. Named in honour of Alexander Graham Bell (1847–1922), it was adopted by Bell Telephone Laboratories and CCITT in the 1920s–1930s. Sound pressure level: L_p = 20 × log₁₀(p/p₀), where p₀ = 20 µPa in air (ISO 1683). Key SPL reference points: 0 dB SPL = threshold of human hearing; 60 dB SPL = normal conversation at 1 m; 85 dB SPL = NIOSH 8-hour occupational limit; 120 dB SPL = pain threshold; 194 dB SPL = theoretical maximum undistorted plane wave in air at 1 atm. In digital audio (AES17, IEC 61606), 0 dBFS = maximum digital full-scale level. In RF engineering, 0 dBm = 1 mW; Wi-Fi signal strength ranges from −30 dBm (excellent) to −90 dBm (unusable). 1 dB = 0.1 B = ln(10)/20 Np ≈ 0.11513 Np.

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