Below you can find logos, similar to the Dolby 1.

Dolby Surround Pro Logic Dolby Surround Pro Logic vector
Dolby Digital Surround EX Dolby Digital Surround EX vector
Dolby B C NR Dolby B C NR vector
Dolby Laboratories Dolby Laboratories vector
Dolby Digital Pro Logic II Dolby Digital Pro Logic II vector
Dolby Surround Pro Logic II Dolby Surround Pro Logic II vector
Dolby Virtual Surround Dolby Virtual Surround vector
Dolby MLP Lossless Dolby MLP Lossless vector
Dolby Digital 5 1 Dolby Digital 5 1 vector
simb dolby pro logic simb dolby pro logic vector
Dolby digital Dolby digital  vector
Dolby Dolby vector
Dolby System Dolby System  vector
Dolby Digital Dolby Digital vector
Dolby B Noise Reduction 29 Dolby B Noise Reduction 29 vector