Quoted:
It depends. If you are audio or video recording a conversation you are not a party to you could be arrested.
That is partially true. it is NOT unlawful to video persons without their knowledge in general public places.
Texas Penal code
Sec. 21.15. IMPROPER PHOTOGRAPHY OR VISUAL RECORDING.
(a) In this section, "promote" has the meaning assigned by Section 43.21.
(b) A person commits an offense if the person:
(1) photographs or by videotape or other electronic means records, broadcasts, or transmits a visual image of another at a location that is not a bathroom or private dressing room:
(A) without the other person's consent; and
(B) with intent to arouse or gratify the sexual desire of any person;
(2) photographs or by videotape or other electronic means records, broadcasts, or transmits a visual image of another at a location that is a bathroom or private dressing room:(A) without the other person's consent; and
(B) with intent to:(i) invade the privacy of the other person; or
(ii) arouse or gratify the sexual desire of any person; or
(3) knowing the character and content of the photograph, recording, broadcast, or transmission, promotes a photograph, recording, broadcast, or transmission described by Subdivision (1) or (2).
(c) An offense under this section is a state jail felony.
(d) If conduct that constitutes an offense under this section also constitutes an offense under any other law, the actor may be prosecuted under this section or the other law.
(e) For purposes of Subsection (b)(2), a sign or signs posted indicating that the person is being photographed or that a visual image of the person is being recorded, broadcast, or transmitted is not sufficient to establish the person's consent under that subdivision.
Below are the relevant sections for audio recording.
Sec. 16.02. UNLAWFUL INTERCEPTION, USE, OR DISCLOSURE OF WIRE, ORAL, OR ELECTRONIC COMMUNICATIONS
(b) A person commits an offense if the person:
(1) intentionally intercepts, endeavors to intercept, or procures another person to intercept or endeavor to intercept a wire, oral, or electronic communication
(4) a person not acting under color of law intercepts a wire, oral, or electronic communication, if:
(A) the person is a party to the communication; or
(B) one of the parties to the communication has given prior consent to the interception, unless the communication is intercepted for the purpose of committing an unlawful act;
As a former Private Investigator I made sure I was well versed in the laws regarding this type of thing. ;)