Abstract: A glass cleaning formulation comprises a mixture of the sodium salts of sulphated alkyl phenoxy polyethoxy ethanols which are anionic in classification, citric acid and a fluorinated hydrocarbon surface active agent blended in an alcoholic base.

Abstract: A hearing protector for providing protection from high volume sound waves. The protector is a headset including earmuffs, at least one of which contains a microphone for receiving sound waves and a speaker for transmitting sound waves to the ear of a person wearing the headset. The signal to the speaker is filtered to reduce the amplitude of any frequency components outside of a predetermined audio frequency range. A CMOS integrated circuit is connected as an active voltage sensitive variable resistance element of a control circuit for automatically limiting the volume of the sound waves provided by the speaker, in response to variations in the level of the sound received within the predetermined audio frequency range.