A technique is directed to controlling speaker volume of a speaker of a portable communications device (e.g., a cellular telephone, a cordless hand phone, a combination of a cellular phone and a hands-free ear piece, etc.). The technique involves receiving an environmental signal from an environmental microphone of the portable communications device. The technique further involves identifying a level of environmental noise based on the environmental signal, and adjusting the speaker volume of the speaker of the portable communications device (e.g., ringer volume, voice output volume, etc.) based on the identified level of environmental noise. Such operation enables a user to accommodate a variety of settings without burdening the user with ongoing manual volume control of the portable communications device.