Talk radio is a radio format containing discussion about topical issues. Most shows are regularly hosted by a single individual, and often feature interviews with a number of different guests. Talk radio typically includes an element of listener participation, usually by broadcasting live conversations between the host and listeners who "call in" (usually via telephone) to the show. Listener contributions are usually screened by a show's producer(s) in order to maximize audience interest and, in the case of commercial talk radio, attract advertisers. Generally, the shows are organized into segments, each separated by a pause for advertisements; however, in public or non-commercial radio, music is sometimes played in place of commercials to separate the program segments. Variations of talk radio include conservative talk, hot talk, progressive talk (or liberal talk) and sports talk.
Starting around 2005, the technology for Internet-based talk-radio shows became cost effective. Now, it is possible for an individual to use a variety of services to host an Internet-based talk-radio show without investing any of their own capital.
Talk radio is not limited to the AM band. "Non-commercial" usually referred to as "public radio," which is located in a reserved spectrum of the FM band, also broadcasts talk programs. Commercial all-talk stations can also be found on the FM band in many cities across the US. These shows often rely less on political discussion and analysis than their AM counterparts, and often employ the use of pranks and "bits" for entertainment purposes. In the United States and Canada, satellite radio services offer uncensored "free-wheeling" original programming, such as The Howard Stern Show and The Opie & Anthony Show, formerly featured on terrestrial, government-censored radio. ABC News & Talk is an example of "rebagging" for the digital airwaves shows featured on their terrestrial radio stations.
According to Arbitron, the top five programs are Rush Limbaugh, Sean Hannity, Glenn Beck, Mark Levin, and Michael Savage. Other top-rated, conservative, less-political commentators include Laura Schlessinger (whose show, Dr. Laura, features personal & interpersonal advice), Bruce Williams, (whose show focuses on banking, business, and personal finances), and Luis de la Garza whose TV and Radio simulcast caters to the Hispanic audience.
Expressing and debating political opinions has been a staple of radio since the medium's infancy. Aimee Semple McPherson began her radio broadcasts in the early 1920s and even purchased her own station, KFSG which went on the air in February 1924; by the mid-1930s, controversial radio priest Father Charles Coughlin's radio broadcasts were reaching millions per week. There was also a national current events forum called America's Town Meeting of the Air which broadcast once a week starting in 1935. It featured panel discussions from some of the biggest newsmakers and was among the first shows to allow audience participation: members of the studio audience could question the guests or even heckle them.
Talk radio as a listener-participation format has existed since at least the mid-1940s. Working for New York's WMCA in 1945, Barry Gray was bored with playing music and put a telephone receiver up to his microphone to talk with bandleader Woody Herman. Soon followed by listener call-ins, this is often credited as the first instance of talk radio, and Gray is often billed as "The hot mama of Talk Radio."
Author Bill Cherry proposed George Roy Clough as the first to invite listeners to argue politics on a call-in radio show at KLUF, his station in Galveston, Texas, as a way to bring his own political views into listeners' homes. (He later became mayor of Galveston.) Cherry gives no specific date, but the context of events and history of the station would seem to place it also in the 1940s, perhaps earlier. The format was the classic mode in which the announcer gave the topic for that day, and listeners called in to debate the issue.
In 1948 Alan Courtney – New York disk jockey and co-composer of the popular song, "Joltin' Joe Dimaggio" – began a call-in program for the Storer station in Miami, Florida (WGBS) and then on Miami's WQAM, WINZ and WCKR the "Alan Courtney Open Phone Forum" flourished as an avowedly conservative and anti-communist political forum with a coverage area over the Southeastern U.S. and Cuba.
Two radio stations—KMOX, 1120 AM in St. Louis, Missouri, and KABC, 790 AM in Los Angeles—adopted an all-talk show format in 1960, and both claim to be the first to have done so. KABC station manager Ben Hoberman and KMOX station manager Robert Hyland independently developed the all-talk format. KTKK, 630 in Salt Lake City, then known as KSXX, adopted a full time talk schedule in 1965 and has claimed to have been the third station in the country to have done so. KSXX started with all local talent, and KTKK today has a larger protion of its schedule featuring local talent than most other stations that run a full schedule of talk.
Radio Monitor on the NBC Radio Network was probably the first Talk oriented radio network. Broadcasting from its 30 Rockefeller Plaza studios. Personalities such as Joe Garagiola, Bill Cullen and a host of other top talent were heard "coast to coast."
In the 1970s and early 1980s, as many listeners abandoned AM music formats for the high fidelity sound of the FM radio dial, the Talk Radio format began to catch on in more large cities. Former music stations such as KLIF, Dallas, Texas),WLW (Cincinnati, Ohio), WHAS (Louisville, Kentucky), WHAM (Rochester, New York), WLS (Chicago, Illinois), KFI (Los Angeles, California), WRKO (Boston, Massachusetts), and WABC (New York, New York) made the switch to all-talk as their ratings slumped due to listener migration to the FM band.
The United States saw dramatic growth in the popularity of talk radio during the 1990s. The repeal of the FCC fairness doctrine (which had required that stations provide free air time for responses to any controversial opinions that were broadcast) in 1987 provided an opportunity for a kind of partisan programming that had not previously existed. Pew researchers found in 2004 that 17% of the public regularly listens to talk radio. This audience is mostly male, middle-aged and conservative. Among those who regularly listen to talk radio, 41% are Republican and 28% are Democrats. Furthermore, 45% describe themselves as conservatives, compared with 18% who say they are liberal.
The most successful pioneer in the 1990s talk radio movement in the US was the politically conservative commentator Rush Limbaugh, whose show comes from Clear Channel Communications-owned Premiere Radio Networks. Limbaugh's success demonstrated that there was a nationwide market for passionately-delivered conservative commentary on contemporary news, events, and social trends. Other radio talk show hosts (who describe themselves as either conservative or libertarian) have also had success as nationally-syndicated hosts, including Hugh Hewitt, Sean Hannity, Jon Arthur, Mark Levin, Michael Medved, Laura Ingraham, Neal Boortz, Michael Savage, Bill O'Reilly, and Glenn Beck.
The Salem Radio Network syndicates a group of religiously-oriented Republican activists, including evangelical Christian Hugh Hewitt and Jewish conservatives Dennis Prager and Michael Medved; these are mostly distributed in a 24-hour network format among Salem's own stations, and they generally earn ratings much less than their syndicated counterparts.
In the Summer of 2007, conservative talk show hosts mobilized public opposition to the McCain-Kennedy immigration reform bill, which eventually failed. Conservative hosts Limbaugh, Ingraham, Bennett, Prager, Hannity, Beck, Levin and Hewitt coalesced around endorsing former Massachusetts governor Mitt Romney for president at the end of January 2008 (after Fred Thompson, the described favorite of some of the hosts, dropped out), in an effort to oppose the nomination of Sen. John McCain  ; however, Romney suspended his campaign in February of the same year, and endorsed McCain. During the primaries, Limbaugh in particular had endorsed a plan to do whatever it took to prolong the Democrats' nomination by encouraging political conservatives to cross over to the Democrats and voting for the trailing candidate, a plan he calls "Operation Chaos." In 2009, conservative talk hosts also lent their unified support for Congressional candidate Doug Hoffman a third-party candidate who was running in a special election against a liberal Republican (Dierdre Scozzafava) and a mainstream Democrat (Bill Owens). The unified support from the conservative base helped propel Hoffman to frontrunner status and effectively killed Scozzafava's campaign, forcing her to drop out of the race several days before the election. This effort backfired on the conservative hosts, as the Democratic candidate Owens won. Local hosts, such as Los Angeles's John and Ken, have also proven effective in influencing the political landscape.
Libertarians such as Dennis Miller (based in Los Angeles), Jon Arthur, Host Of Jon Arthur Live! (based in Florida), Patti Brooks KGMI (based in the Pacific Northwest),Free Talk Live (based in New Hampshire), Penn Jillette (based in Las Vegas), Jay Severin (based in Boston, Massachusetts), and Mark Davis (based in Ft. Worth and Dallas, Texas) have also achieved some success. Many of these hosts also publish books, write newspaper columns, appear on television, and give public lectures (Limbaugh, again, was a pioneer of this model of multi-media punditry).
There had been some precursors for talk radio, such as the Los Angeles-area controversialist Joe Pyne, who would attack callers on his program in the early 1960s – one of his famous insults was "gargle with razor blades!"; the similar Bob Grant in New York City; and Wally George in Southern California. Grant remains on the air to this day.
Politically liberal talk radio aimed at a national audience has also emerged. Air America, a network featuring The Al Franken Show, was founded in 2004. It billed itself as a "progressive alternative" to the conservative talk radio shows. Liberal Talk Radio, as a whole, gained considerable momentum during the Bush administration. So much so that Clear Channel eventually bought Air America and it's ratings continued to increase.
Some prominent examples of liberal talk radio shows currently in national syndication include: Dial Global talk show hosts Ed Schultz, Stephanie Miller, Thom Hartmann, and Bill Press; The Young Turks; Fox News host Alan Colmes, First Amendment Radio Network Libertarian host Jon Arthur, Air America hosts Lionel and Rachel Maddow, self-distributed Mike Malloy and Premiere's Randi Rhodes. In some markets, local liberal hosts have existed for years, such as the British talk host Michael Jackson (who was on the air at KABC in Los Angeles beginning in 1968 and is currently at KGIL); Bernie Ward in San Francisco; Jack Ellery in New Jersey and Tampa; Dave Ross in Seattle, and Marc Germain in Los Angeles. A few earlier syndicated programs were hosted by prominent Democrats who were not experienced broadcasters, such as Jim Hightower, Jerry Brown, Mario Cuomo and Alan Dershowitz; these met with limited success, and Air America has been faced with various legal and financial problems.
Air America was sold to a new owner in March 2007, hired well-known programmer David Bernstein, and began its "re-birth." Bernstein subsequently left in early 2008, but the struggling network remained on the air with a revamped line-up.
On January 21, 2010, Air America Radio ceased live programming citing a difficulty with the current economic environment, and announced that it would file for Chapter 7 bankruptcy production and liquidate itself. The network will end operations on January 25, 2010. 
Liberal opinion radio has long existed on the Pacifica network, though only available in a small number of major cities, and in formats that more often act as a volunteer-run community forum than as a platform for charismatic hosts who would be likely to attract a large audience. The one major host to become popular on the network is Amy Goodman, whose Democracy Now! interview and journalism program is broadcast nationwide. Conservative critics have long complained that the long-format news programming on National Public Radio (NPR) shows a liberal bias, although this is disputed by Fairness and Accuracy in Reporting (FAIR), which found that, for example, "representatives of think tanks to the right of center outnumbered those to the left of center by more than four to one: 62 appearances to 15."  NPR itself denies any partisan agenda. Politically oriented talk programs on the network are in the mold of Talk of the Nation, which is designed to be a soundboard for the varied opinions of listeners.
Clear Channel, with nearly 1,300 radio stations under its ownership - along with other owners - has in recent years added more liberal talk stations to their portfolio. These have primarily come from the conversion of AM facilities, most of which formerly had adult standards formats. Many complaints (all radio stations are required by the FCC to maintain, in their public files, copies of all correspondence from the public relating to station operations - for a period of three years from receipt) have been received from fans of this musical genre (Tony Bennett, Frank Sinatra, big band music," etc.) - but the left-leaning talk programming leans toward a much younger demographic, a group that advertisers covet. More recently, however, Clear Channel has been dropping liberal formats in favor of their own Fox Sports Radio network.
Hot talk, also called "FM talk" or "shock talk", is a talk radio format geared predominantly to a male demographic between the ages of 18-49. The subject matter generally consists of subjects pertaining to pop culture rather than the political talk found on AM radio.
Clear Channel Communications has a select few hot talk stations under the moniker Real Radio, while CBS Radio once had a larger chain of hot talkers known as Free FM, though this brand has been abandoned. It is usually found on FM radio music stations in morning drive, as the actual hot talk formatted stations have only achieved mediocre success as a whole compared to AM or conservative talk radio. More recently the genre has been showing up on satellite radio. The genre has spread to internet radio, with Hot Talk programming appearing on several stations, such as UFO Radio and ThereIsNoRadio. Like satellite radio, these shows are not restricted by the FCC and advertisements are rare.
Other US hosts specialize in talk radio comedy, such as Phil Hendrie, who voices his own fictional guests and occasionally parodies other programs. Sports talk radio can be found locally and nationally in the US (with the networks ESPN Radio, Fox Sports Radio, and Sporting News Radio, as well as nationally syndicated host Jim Rome). Sports talk stations like WFAN in New York City and WEEI in Boston have done well in the ratings (aided by baseball and football game broadcasts).
Talk radio in the United Kingdom is popular, though not as much as music radio. Nationwide talk stations include BBC Radio 4, BBC Radio Five Live, BBC 7 and talkSPORT. Regional stations include BBC Radio Scotland and BBC Radio Wales. Many BBC Local Radio stations and some commercial stations offer a talk format, for example, BBC London, the BBC's flagship local station. Other notable commercial talk stations include London's LBC which pioneered the newstalk format in Europe. LBC currently operates two services in London - LBC 97.3, a newstalk station on FM; and LBC News 1152, a rolling news station on AM; also, Talk 107 in Edinburgh. There are many specialised talk services such as Bloomberg, a financial news station; Oneword, which broadcast plays and stories but was closed in 2008 and Radio4 which broadcasts speech and entertainment programming - Radio 5Live is a talk/sport station.
Talk radio expanded dramatically when the BBC's monopoly on radio broadcasting was ended in the 1970s with the launch of Independent Local Radio.
Some notable British talk radio presenters include Tommy Boyd, James Whale, Steve Allen, Jon Gaunt, Nick Abbot, James Stannage, George Galloway, Ian Collins, Brian Hayes, Scottie McClue, Nicky Campbell and Simon Mayo. Pete Price on CityTalk is also known as the DJ who rushed to the aid of a regular caller who died live on air during a call. Previously, he kept a suicidal teenager talking for 45 minutes before meeting him to convince him against that course of action.
In contrast to talk radio stations in the United States where syndicated programs tend to make up a significant part of most schedules, privately owned Canadian talk radio stations tend to be predominantly local in programming and focus. There is no Canadian content requirement for talk radio, or "spoken word," programming, unless the individual station's license expressly stipulates such a requirement, which most do not. (In Canada, prospective radio stations may propose certain restrictions on their license in order to gain favor with the CRTC and have an easier time obtaining a license.)
The only nationally-syndicated, politically oriented weekday talk radio show in Canada is Adler On Line, hosted by Charles Adler and heard on eleven stations across the country. Until 2006, Peter Warren's Warren on the Weekend was heard Saturdays and Sundays. Both programs are or were distributed by the Corus Radio Network and, coincidentally, both hosts had hosted different morning call-in programs in the same time slot on Winnipeg, Manitoba's CJOB 680 before they became nationally syndicated (Adler's show still originates from CJOB and retained its original title, while Warren was based in Victoria, British Columbia.) Prior to Adler On Line, Corus had syndicated Rutherford, hosted by neo conservative Dave Rutherford and originating from its Calgary station, QR77. Rutherford is no longer syndicated nationally but continues to air in Calgary, Edmonton, and London.
Other Canadian talk radio programs which have been syndicated to different markets include:
The two largest talk radio networks in Canada are the publicly owned Canadian Broadcasting Corporation's English language CBC Radio One and French language Première Chaîne. These stations typically produce their own local morning and afternoon programs and regional noon hour programs to go along with the network programming that is aired during the rest of the day. Both networks are commercial-free. CBC Radio One's flagship national talk program is the weekend Cross Country Checkup, which has been broadcast since 1965.
CFRA (580 on the am dial) in Ottawa (was part of the CHUM network which is now part of CTV) has a large and dedicated listening audience. The station is heard throughout the Ottawa valley and on the internet. A couple of key programs focus on local political and world issues. Lowell Green provides a conservative biased review of events while Michael Harris has a left leaning bias. The Lowell Green show as of Sept-08 goes from 10am - noon Monday to Friday. The Michael Harris show is from 1-3 Monday to Thursday.
Privately owned talk radio syndication networks in Canada are generally formed for the purposes of sharing programs across a group of stations with common ownership, although some are formed to distribute their one or two talk radio programs to a number of stations regardless of ownership. The largest of these is the Corus Radio Network. Others include the CHUM Radio Network and the Standard Radio Network.
Syndicated programs from the United States which air on Canadian radio stations include:
Traditionally, politically-driven talk radio from the United States does not normally air on Canadian stations, with a few scattered exceptions.
In Australia, talk radio is known as talkback radio. The most popular talkback radio station historically has been Sydney's 2UE, whose populist programs like The John Laws Morning Show, are widely syndicated across the continent. In recent years though, 2UE been eclipsed by its Sydney rival 2GB after the defection of 2UE most popular talkback host, Alan Jones.
In the 1990s and 2000s, "Talkback" on FM has been attempted. The Spoonman was a program hosted by Brian Carlton on the triple m network in the late 1990s and returned in 2005 for 3 and a half years, the show wrapping up in 2008. It was a show which covered many topics, but the 'Hot Talk' format in the USA would probably be the best way to describe the program.
Talkback radio has historically been an important political forum in Australia and functions much like the cable news televisions in the United States, with live and 'saturated' coverage of political issues.
In New Zealand, as in Australia, the talk radio format is popularly known as talkback radio. The major radio networks broadcasting in the talk radio format are Newstalk ZB and Radio Live. Their sports sister networks, Radio Sport and LiveSport also largely broadcast in talk format. Other stations such as Radio New Zealand National also feature talkback components.