Abstract: A self-administrable anti-fertility composition comprising a progestational compound in an amount effective for alteration of cervical mucus secretions in a manner unfavorable to fertility without systemic absorption and a pharmaceutically acceptable vehicle. A typical composition is a foamable aqueous emulsion containing an anionic surfactant, propylene glycol and an amount of progesterone effective to provide a dose of from about 10 micrograms to about 5 miligrams. The composition may be foamed by dispensing with a syringe or by dispensing from an aerosol container.

Abstract: Sound signals are processed for compression or expansion utilizing storage and frequency transformation into storage delay lines operated alternately to transform alternate segments of the sound signal respectively with the outputs of the two delay lines combined to produce a continuous sound signal output with the frequency components thereof transformed.