Terms cont’d. Dynamics
Dec 16, 2015
Dynamics
• Relative loudness or softness of a sound.
• A trumpet soft is still louder than an acoustic guitar played loud!
SPL - Sound Pressure Level
• Hearing damage (over long-term exposure, need not be continuous)
• 85 dB
SPL - Sound Pressure Level
• Theoretical limit for undistorted sound at 1 atmosphere environmental pressure
• ~194.094 dB
SPL - Sound Pressure Level
• Shockwave (distorted sound waves > 1 atm; waveform valleys are clipped at zero pressure)
• >194 dB
Musical Dynamics
• Musical Dynamics• A piece of music may change in dynamic
level throughout.• Live music is especially good for hearing
dynamics.• Subtle variations in a performance by
musicians, being sensitive to the sounds around them.
Musical Dynamics
• A recording on CD is also excellent for capturing dynamics, as the available dynamic range is far better than on other recording media (tapes, records, and other analog formats).
Compression
Radio and mp3 formats are not ideal for hearing dynamics.
The recording is modified with Compression.
Compression “squeezes” the dynamic levels, making loud sounds softer, and soft sounds louder.
Normalize
• A way of modifying sound to “peak” at the maximum volume.
• Analysis of a computer sound byte will display the current volume level, as well as show the maximum potential volume before distortion / clipping / overload.
Normalize
• Before After
QuickTime™ and a decompressor
are needed to see this picture.QuickTime™ and a decompressorare needed to see this picture.
QuickTime™ and a decompressorare needed to see this picture.
Add compression
The Loudness Wars
• The movement in audio recording and production that strives to get the most audio density into each recording.
• Record a sound, compress it, normalize it, compress it, normalize it, compress it, etc.
• Eliminates the distinction between loud and soft - everything is loud or “hot”.