Public companies are required to announce their quarterly earnings ("earnings calls") and other significant events, and they generally hold conference calls with stock analysts to explain the news ("analyst calls"). As of 2002, the SEC requires companies to make these calls available to the public.
Transcripts of these conference calls are published by several companies and made available through even more. Seeking Alpha transcripts are available free through the Seeking Alpha Transcript Center and NASDAQ Call Transcripts.
If you can't find the transcript you need for free, you can buy transcripts through the Alacra Store, Bloomberg, Fair Disclosure Wire on Lexis (NEWS;FDW), Capital IQ, LIVEDGAR, and other vendors. On LIVEDGAR, use the Full-Text Search database; search on the date and, in the free text field: [company name] p/175 (conference w/7 earning*).
Alerts Capital IQ lets you set up Alerts to tell you when a scheduled Conference Call is coming up, or when transcripts are available (subscription required).
Audio recordings of conference calls may be posted free on the company's Web site. If not, try Earnings.com, Earnings Cast and/or Yahoo! Finance.