A cordless FM microphone could also be passed around as needed. For a medium size meeting, the tables could be equipped with a single microphone for every two or three people. Conference microphones, which pick-up the speech of several people in the vicinity, are also available. It involves connecting both a microphone and listening attachment to the same device, an amplifier. This is not wireless, so could not transmit across a distance, although in some cases it can be used with several microphones.
Portable amplifiers strap onto the telephone handset.
They are convenient for travel but are not usually practical for regular use. In-line and handset amplifiers are the most popular choices because they are relatively inexpensive and generally equal in effectiveness. Most amplifiers designed for hard of hearing people offer a 20dB gain, although devices with gains up to 40dB are also available. Telephone products, such as these, are sometimes available free of charge through equipment distribution programs. The problem sometimes occurs at hotels, which loan amplifiers to customers, to use with their room phones.